diff --git a/examples/protobuf/sensors/client/sensorclient.cpp b/examples/protobuf/sensors/client/sensorclient.cpp
index 3d0f3b70..8aa2acbd 100644
--- a/examples/protobuf/sensors/client/sensorclient.cpp
+++ b/examples/protobuf/sensors/client/sensorclient.cpp
@@ -23,11 +23,11 @@ void SensorClient::receive()
         const auto datagram = m_client.receiveDatagram();
         qt::examples::sensors::tlv::TlvMessage msg;
         msg.deserialize(&m_serializer, datagram.data());
-        if (m_serializer.deserializationError()
+        if (m_serializer.lastError()
                 != QAbstractProtobufSerializer::NoError) {
             qWarning().nospace() << "Unable to deserialize datagram ("
-                       << m_serializer.deserializationError() << ")"
-                       << m_serializer.deserializationErrorString();
+                       << m_serializer.lastError() << ")"
+                       << m_serializer.lastErrorString();
             continue;
         }
 //! [0]
@@ -55,11 +55,11 @@ void SensorClient::receive()
         }
         }
 
-        if (m_serializer.deserializationError()
+        if (m_serializer.lastError()
                 != QAbstractProtobufSerializer::NoError) {
             qWarning().nospace() << "Unable to deserialize message ("
-                       << m_serializer.deserializationError() << ")"
-                       << m_serializer.deserializationErrorString();
+                       << m_serializer.lastError() << ")"
+                       << m_serializer.lastErrorString();
             continue;
         }
     }
diff --git a/src/protobuf/qabstractprotobufserializer.cpp b/src/protobuf/qabstractprotobufserializer.cpp
index 52b74bcf..279b6eaf 100644
--- a/src/protobuf/qabstractprotobufserializer.cpp
+++ b/src/protobuf/qabstractprotobufserializer.cpp
@@ -33,18 +33,19 @@ QT_BEGIN_NAMESPACE
 */
 
 /*!
-    \enum QAbstractProtobufSerializer::DeserializationError
+    \enum QAbstractProtobufSerializer::Error
+    \since 6.8
 
     This enum contains possible errors that can occur during deserialization.
-    When an error occurs, call deserializationErrorString() to get a
+    When an error occurs, call lastErrorString() to get a
     human-readable error message.
 
     \value NoError                      No error occurred.
     \value InvalidHeaderError           Something went wrong while attempting to
                                         decode a header in the message.
-    \value NoDeserializerError          While deserializing a message, no
-                                        deserializer was found for a type in the
-                                        message.
+    \value UnknownTypeError             While serializing or deserializing a
+                                        message, no deserializer was found
+                                        for a message field.
     \value UnexpectedEndOfStreamError   While deserializing a message, the
                                         stream ended unexpectedly.
     \value InvalidFormatError           The data has invalid format. For example
@@ -77,15 +78,21 @@ QT_BEGIN_NAMESPACE
 */
 
 /*!
-   \fn QAbstractProtobufSerializer::DeserializationError QAbstractProtobufSerializer::deserializationError() const
-   Returns the last deserialization error for the serializer instance.
-   \sa deserializationErrorString()
+   \fn QAbstractProtobufSerializer::Error QAbstractProtobufSerializer::lastError() const
+   \since 6.8
+
+   Returns the last error for the serializer instance.
+
+   \sa lastErrorString()
 */
 
 /*!
-   \fn QString QAbstractProtobufSerializer::deserializationErrorString() const
-   Returns the last deserialization error string for the serializer instance.
-   \sa deserializationError()
+   \fn QString QAbstractProtobufSerializer::lastErrorString() const
+   \since 6.8
+
+   Returns the last error string for the serializer instance.
+
+   \sa lastError()
 */
 
 /*!
diff --git a/src/protobuf/qabstractprotobufserializer.h b/src/protobuf/qabstractprotobufserializer.h
index 11986c6d..f083f476 100644
--- a/src/protobuf/qabstractprotobufserializer.h
+++ b/src/protobuf/qabstractprotobufserializer.h
@@ -19,10 +19,10 @@ class QProtobufMessage;
 class Q_PROTOBUF_EXPORT QAbstractProtobufSerializer
 {
 public:
-    enum DeserializationError : uint8_t {
+    enum Error : uint8_t {
         NoError,
         InvalidHeaderError,
-        NoDeserializerError,
+        UnknownTypeError,
         UnexpectedEndOfStreamError,
         InvalidFormatError,
     };
@@ -32,8 +32,8 @@ public:
 
     virtual ~QAbstractProtobufSerializer();
 
-    virtual DeserializationError deserializationError() const = 0;
-    virtual QString deserializationErrorString() const = 0;
+    virtual Error lastError() const = 0;
+    virtual QString lastErrorString() const = 0;
 
 protected:
     virtual QByteArray serializeMessage(const QProtobufMessage *message) const = 0;
diff --git a/src/protobuf/qprotobufjsonserializer.cpp b/src/protobuf/qprotobufjsonserializer.cpp
index ed7155cc..23372895 100644
--- a/src/protobuf/qprotobufjsonserializer.cpp
+++ b/src/protobuf/qprotobufjsonserializer.cpp
@@ -536,7 +536,7 @@ public:
                 }
 
                 while (!array.isEmpty()
-                       && deserializationError == QAbstractProtobufSerializer::NoError) {
+                       && lastError == QAbstractProtobufSerializer::NoError) {
                     activeValue = array.takeAt(0);
                     if (deserializeObject(&propertyIt.addNext()))
                         propertyIt.push();
@@ -544,19 +544,19 @@ public:
                 ok = propertyData.isValid();
             } else {
                 while (!activeValue.isNull()
-                       && deserializationError == QAbstractProtobufSerializer::NoError) {
+                       && lastError == QAbstractProtobufSerializer::NoError) {
                     if (deserializeObject(&propertyIt.addNext()))
                         propertyIt.push();
                 }
             }
-            ok = deserializationError == QAbstractProtobufSerializer::NoError;
+            ok = lastError == QAbstractProtobufSerializer::NoError;
             return propertyData;
         }
 
         auto handler = QtProtobufPrivate::findHandler(metaType);
         if (handler.deserializer) {
             while (!activeValue.isNull()
-                   && deserializationError == QAbstractProtobufSerializer::NoError) {
+                   && lastError == QAbstractProtobufSerializer::NoError) {
                 handler
                     .deserializer([this](QProtobufMessage
                                              *message) { return this->deserializeObject(message); },
@@ -571,7 +571,7 @@ public:
                 if (!ok)
                     setInvalidFormatError();
             } else {
-                setDeserializationError(QAbstractProtobufSerializer::NoDeserializerError,
+                setDeserializationError(QAbstractProtobufSerializer::UnknownTypeError,
                                         QCoreApplication::
                                             translate("QtProtobuf",
                                                       "No deserializer is registered for type %1")
@@ -682,11 +682,11 @@ public:
         return storeCachedValue(message);
     }
 
-    void setDeserializationError(QAbstractProtobufSerializer::DeserializationError error,
+    void setDeserializationError(QAbstractProtobufSerializer::Error error,
                                  const QString &errorString)
     {
-        deserializationError = error;
-        deserializationErrorString = errorString;
+        lastError = error;
+        lastErrorString = errorString;
     }
 
     void setUnexpectedEndOfStreamError()
@@ -706,9 +706,8 @@ public:
 
     void clearError();
 
-    QAbstractProtobufSerializer::DeserializationError deserializationError =
-            QAbstractProtobufSerializer::NoDeserializerError;
-    QString deserializationErrorString;
+    QAbstractProtobufSerializer::Error lastError = QAbstractProtobufSerializer::NoError;
+    QString lastErrorString;
     QJsonValue activeValue;
 
     static SerializerRegistry handlers;
@@ -755,8 +754,8 @@ void QProtobufJsonSerializerPrivate::serializeObjectImpl(const QProtobufMessage
 
 void QProtobufJsonSerializerPrivate::clearError()
 {
-    deserializationError = QAbstractProtobufSerializer::NoError;
-    deserializationErrorString.clear();
+    lastError = QAbstractProtobufSerializer::NoError;
+    lastErrorString.clear();
 }
 
 QProtobufJsonSerializer::QProtobufJsonSerializer() : d_ptr(new QProtobufJsonSerializerPrivate)
@@ -767,21 +766,20 @@ QProtobufJsonSerializer::~QProtobufJsonSerializer() = default;
 
 /*!
    Returns the last deserialization error for the serializer instance.
-   \sa deserializationErrorString()
+   \sa lastErrorString()
 */
-QAbstractProtobufSerializer::DeserializationError
-QProtobufJsonSerializer::deserializationError() const
+QAbstractProtobufSerializer::Error QProtobufJsonSerializer::lastError() const
 {
-    return d_ptr->deserializationError;
+    return d_ptr->lastError;
 }
 
 /*!
    Returns the last deserialization error string for the serializer instance.
-   \sa deserializationError()
+   \sa lastError()
 */
-QString QProtobufJsonSerializer::deserializationErrorString() const
+QString QProtobufJsonSerializer::lastErrorString() const
 {
-    return d_ptr->deserializationErrorString;
+    return d_ptr->lastErrorString;
 }
 
 QByteArray QProtobufJsonSerializer::serializeMessage(const QProtobufMessage *message) const
diff --git a/src/protobuf/qprotobufjsonserializer.h b/src/protobuf/qprotobufjsonserializer.h
index 41e690b6..2fe8307c 100644
--- a/src/protobuf/qprotobufjsonserializer.h
+++ b/src/protobuf/qprotobufjsonserializer.h
@@ -21,8 +21,8 @@ public:
     QProtobufJsonSerializer();
     ~QProtobufJsonSerializer() override;
 
-    DeserializationError deserializationError() const override;
-    QString deserializationErrorString() const override;
+    Error lastError() const override;
+    QString lastErrorString() const override;
 
 protected:
     QByteArray serializeMessage(const QProtobufMessage *message) const override;
diff --git a/src/protobuf/qprotobufserializer.cpp b/src/protobuf/qprotobufserializer.cpp
index d02048af..b2d6a0e8 100644
--- a/src/protobuf/qprotobufserializer.cpp
+++ b/src/protobuf/qprotobufserializer.cpp
@@ -231,8 +231,8 @@ void QProtobufSerializerPrivate::setUnexpectedEndOfStreamError()
 
 void QProtobufSerializerPrivate::clearError()
 {
-    deserializationError = QAbstractProtobufSerializer::NoError;
-    deserializationErrorString.clear();
+    lastError = QAbstractProtobufSerializer::NoError;
+    lastErrorString.clear();
 }
 
 bool QProtobufSerializer::deserializeMessage(QProtobufMessage *message, QByteArrayView data) const
@@ -644,7 +644,7 @@ bool QProtobufSerializerPrivate::deserializeProperty(QProtobufMessage *message)
         qProtoWarning() << "No deserializer for type" << metaType.name();
         QString error = QString::fromUtf8("No deserializer is registered for type %1")
                             .arg(QString::fromUtf8(metaType.name()));
-        setDeserializationError(QAbstractProtobufSerializer::NoDeserializerError,
+        setDeserializationError(QAbstractProtobufSerializer::UnknownTypeError,
                                 QCoreApplication::translate("QtProtobuf", error.toUtf8().data()));
         return false;
     }
@@ -678,27 +678,27 @@ void QProtobufSerializerPrivate::clearCachedValue()
 
 /*!
    Returns the last deserialization error for the serializer instance.
-   \sa deserializationErrorString()
+   \sa lastErrorString()
 */
-QAbstractProtobufSerializer::DeserializationError QProtobufSerializer::deserializationError() const
+QAbstractProtobufSerializer::Error QProtobufSerializer::lastError() const
 {
-    return d_ptr->deserializationError;
+    return d_ptr->lastError;
 }
 
 /*!
    Returns the last deserialization error string for the serializer instance.
-   \sa deserializationError()
+   \sa lastError()
 */
-QString QProtobufSerializer::deserializationErrorString() const
+QString QProtobufSerializer::lastErrorString() const
 {
-    return d_ptr->deserializationErrorString;
+    return d_ptr->lastErrorString;
 }
 
 void QProtobufSerializerPrivate::setDeserializationError(
-        QAbstractProtobufSerializer::DeserializationError error, const QString &errorString)
+        QAbstractProtobufSerializer::Error error, const QString &errorString)
 {
-    deserializationError = error;
-    deserializationErrorString = errorString;
+    lastError = error;
+    lastErrorString = errorString;
 }
 
 /*!
diff --git a/src/protobuf/qprotobufserializer.h b/src/protobuf/qprotobufserializer.h
index 5861ce45..dfaf265a 100644
--- a/src/protobuf/qprotobufserializer.h
+++ b/src/protobuf/qprotobufserializer.h
@@ -24,8 +24,8 @@ public:
     QProtobufSerializer();
     ~QProtobufSerializer() override;
 
-    DeserializationError deserializationError() const override;
-    QString deserializationErrorString() const override;
+    Error lastError() const override;
+    QString lastErrorString() const override;
 
     void shouldPreserveUnknownFields(bool preserveUnknownFields);
 
diff --git a/src/protobuf/qprotobufserializer_p.h b/src/protobuf/qprotobufserializer_p.h
index 56893e0e..79a0a948 100644
--- a/src/protobuf/qprotobufserializer_p.h
+++ b/src/protobuf/qprotobufserializer_p.h
@@ -517,7 +517,7 @@ public:
                            const QtProtobufPrivate::QProtobufFieldInfo &fieldInfo);
     [[nodiscard]] bool deserializeProperty(QProtobufMessage *message);
 
-    void setDeserializationError(QAbstractProtobufSerializer::DeserializationError error,
+    void setDeserializationError(QAbstractProtobufSerializer::Error error,
                                  const QString &errorString);
     void clearError();
     void setUnexpectedEndOfStreamError();
@@ -525,9 +525,9 @@ public:
     [[nodiscard]] bool storeCachedValue(QProtobufMessage *message);
     void clearCachedValue();
 
-    QAbstractProtobufSerializer::DeserializationError deserializationError =
-            QAbstractProtobufSerializer::NoDeserializerError;
-    QString deserializationErrorString;
+    QAbstractProtobufSerializer::Error lastError =
+            QAbstractProtobufSerializer::UnknownTypeError;
+    QString lastErrorString;
 
     QProtobufSelfcheckIterator it;
     QByteArray result;
diff --git a/tests/auto/grpc/qgrpchttp2channel/tst_qgrpchttp2channel.cpp b/tests/auto/grpc/qgrpchttp2channel/tst_qgrpchttp2channel.cpp
index 0e47ba59..880ea630 100644
--- a/tests/auto/grpc/qgrpchttp2channel/tst_qgrpchttp2channel.cpp
+++ b/tests/auto/grpc/qgrpchttp2channel/tst_qgrpchttp2channel.cpp
@@ -25,12 +25,12 @@ using namespace Qt::StringLiterals;
 class DummySerializer : public QAbstractProtobufSerializer
 {
 public:
-    virtual QAbstractProtobufSerializer::DeserializationError deserializationError() const override
+    virtual QAbstractProtobufSerializer::Error lastError() const override
     {
-        return QAbstractProtobufSerializer::NoDeserializerError;
+        return QAbstractProtobufSerializer::NoError;
     }
 
-    virtual QString deserializationErrorString() const override { return {}; }
+    virtual QString lastErrorString() const override { return {}; }
 
 protected:
     virtual QByteArray serializeMessage(const QProtobufMessage *) const override { return {}; }
diff --git a/tests/auto/protobuf/basic/tst_protobuf_deserialization_complex_maptypes.cpp b/tests/auto/protobuf/basic/tst_protobuf_deserialization_complex_maptypes.cpp
index 7fca9dfd..3700d094 100644
--- a/tests/auto/protobuf/basic/tst_protobuf_deserialization_complex_maptypes.cpp
+++ b/tests/auto/protobuf/basic/tst_protobuf_deserialization_complex_maptypes.cpp
@@ -46,7 +46,7 @@ void QtProtobufMapTypesDeserializationTest::simpleFixed32ComplexMapDeserializeTe
                      QByteArray::fromHex("3a180d0a00000012110810120d320b74656e207369787465656e3a230"
                                          "d2a000000121c080a12183216666f757274792074776f2074656e2073"
                                          "69787465656e3a110d13000100120a080a120632045755543f"));
-    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->deserializationError());
+    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->lastError());
 
     qtprotobufnamespace::tests::SimpleStringMessage stringMsg;
 
@@ -78,7 +78,7 @@ void QtProtobufMapTypesDeserializationTest::simpleSFixed32ComplexMapDeserializeT
             QByteArray::fromHex("4a290dd6ffffff1222121e321c6d696e757320666f757274792074776f2074656e"
                                 "207369787465656e080a4a180d0a0000001211120d320b74656e20736978746565"
                                 "6e08104a110d13000100120a120632045755543f080a"));
-    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->deserializationError());
+    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->lastError());
 
     qtprotobufnamespace::tests::SimpleStringMessage stringMsg;
 
@@ -110,7 +110,7 @@ void QtProtobufMapTypesDeserializationTest::simpleInt32ComplexMapDeserializeTest
             QByteArray::fromHex("1a2f08d6ffffffffffffffff011222121e321c6d696e757320666f757274792074"
                                 "776f2074656e207369787465656e080a1a15080a1211120d320b74656e20736978"
                                 "7465656e08101a1008938004120a120632045755543f080a"));
-    QCOMPARE(serializer->deserializationError(), QAbstractProtobufSerializer::NoError);
+    QCOMPARE(serializer->lastError(), QAbstractProtobufSerializer::NoError);
 
     qtprotobufnamespace::tests::SimpleStringMessage stringMsg;
 
@@ -141,7 +141,7 @@ void QtProtobufMapTypesDeserializationTest::simpleSInt32ComplexMapDeserializeTes
                      QByteArray::fromHex("0a1608a580081210120c320a6d696e7573205755543f080a0a1508141"
                                          "211120d320b74656e207369787465656e08100a200854121c12183216"
                                          "666f757274792074776f2074656e207369787465656e080a"));
-    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->deserializationError());
+    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->lastError());
 
     qtprotobufnamespace::tests::SimpleStringMessage stringMsg;
 
@@ -173,7 +173,7 @@ void QtProtobufMapTypesDeserializationTest::simpleUInt32ComplexMapDeserializeTes
             QByteArray::fromHex(
                     "2a15080a1211120d320b74656e207369787465656e08102a20082a121c12183216666f75727479"
                     "2074776f2074656e207369787465656e080a2a1008938004120a120632045755543f080a"));
-    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->deserializationError());
+    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->lastError());
 
     qtprotobufnamespace::tests::SimpleStringMessage stringMsg;
 
@@ -205,7 +205,7 @@ void QtProtobufMapTypesDeserializationTest::simpleFixed64ComplexMapDeserializeTe
                              "421c090a000000000000001211120d320b74656e207369787465656e0810421509130"
                              "0010000000000120a120632045755543f080a422b09ffffffffffffffff1220121c32"
                              "1a6d696e757320666f757274792074776f2074656e204d41414158082a"));
-    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->deserializationError());
+    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->lastError());
 
     qtprotobufnamespace::tests::SimpleStringMessage stringMsg;
 
@@ -237,7 +237,7 @@ void QtProtobufMapTypesDeserializationTest::simpleSFixed64ComplexMapDeserializeT
                              "522d09d6ffffffffffffff1222121e321c6d696e757320666f757274792074776f207"
                              "4656e207369787465656e080a521c090a000000000000001211120d320b74656e2073"
                              "69787465656e08105215091300010000000000120a120632045755543f080a"));
-    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->deserializationError());
+    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->lastError());
 
     qtprotobufnamespace::tests::SimpleStringMessage stringMsg;
 
@@ -269,7 +269,7 @@ void QtProtobufMapTypesDeserializationTest::simpleInt64ComplexMapDeserializeTest
             QByteArray::fromHex("222f08d6ffffffffffffffff011222121e321c6d696e757320666f757274792074"
                                 "776f2074656e207369787465656e080a2215080a1211120d320b74656e20736978"
                                 "7465656e0810221008938004120a120632045755543f080a"));
-    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->deserializationError());
+    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->lastError());
 
     qtprotobufnamespace::tests::SimpleStringMessage stringMsg;
 
@@ -300,7 +300,7 @@ void QtProtobufMapTypesDeserializationTest::simpleSInt64ComplexMapDeserializeTes
                      QByteArray::fromHex("122608531222121e321c6d696e757320666f757274792074776f20746"
                                          "56e207369787465656e080a121508141211120d320b74656e20736978"
                                          "7465656e0810121008a68008120a120632045755543f080a"));
-    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->deserializationError());
+    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->lastError());
 
     qtprotobufnamespace::tests::SimpleStringMessage stringMsg;
 
@@ -332,7 +332,7 @@ void QtProtobufMapTypesDeserializationTest::simpleUInt64ComplexMapDeserializeTes
             QByteArray::fromHex(
                     "3214080a1210120c320a74656e20656c6576656e080b3220082a121c12183216666f7572747920"
                     "74776f2074656e207369787465656e080a321008938004120a120632045755543f080a"));
-    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->deserializationError());
+    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->lastError());
 
     qtprotobufnamespace::tests::SimpleStringMessage stringMsg;
 
@@ -364,7 +364,7 @@ void QtProtobufMapTypesDeserializationTest::simpleStringComplexMapDeserializeTes
                              "6a140a055755543f3f120b120732053f5755543f080a6a170a0362656e1210120c320"
                              "a74656e20656c6576656e080b6a350a157768657265206973206d7920636172206475"
                              "64653f121c12183216666f757274792074776f2074656e207369787465656e080a"));
-    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->deserializationError());
+    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->lastError());
 
     qtprotobufnamespace::tests::SimpleStringMessage stringMsg;
 
@@ -395,7 +395,7 @@ void QtProtobufMapTypesDeserializationTest::simpleUInt64ComplexMapInvalidLengthD
                      QByteArray::fromHex(
                              "3214080a1210120c320a74656e20656c6576656e080b3220082a121c12183216666f7"
                              "57274792074776f2074656e207369787465656e080a321008938004120a120"));
-    QCOMPARE(serializer->deserializationError(), QAbstractProtobufSerializer::InvalidHeaderError);
+    QCOMPARE(serializer->lastError(), QAbstractProtobufSerializer::InvalidHeaderError);
     QVERIFY(test.mapField().isEmpty());
 }
 
@@ -407,7 +407,7 @@ void QtProtobufMapTypesDeserializationTest::simpleStringComplexMapInvalidLengthD
                              "6a140a055755543f3f120b120732053f5755543f080a6a170a0362656e1210120c320"
                              "a74656e20656c6576656e080b6a350a157768657265206973206d7920636172206475"
                              "64653f121c12183216666f757274792074776f2074656e20736978746565"));
-    QCOMPARE(serializer->deserializationError(),
+    QCOMPARE(serializer->lastError(),
              QAbstractProtobufSerializer::UnexpectedEndOfStreamError);
 
     qtprotobufnamespace::tests::SimpleStringMessage stringMsg;
@@ -435,7 +435,7 @@ void QtProtobufMapTypesDeserializationTest::simpleUInt64ComplexMapCorruptedDeser
             QByteArray::fromHex(
                     "3214080a1210120c320a74656e20656c6576656e080b3221233522345b2183216666f757274792"
                     "074776f2074656e207369787465656e080a321008938004120a120632045755543f080a"));
-    QCOMPARE(serializer->deserializationError(), QAbstractProtobufSerializer::InvalidHeaderError);
+    QCOMPARE(serializer->lastError(), QAbstractProtobufSerializer::InvalidHeaderError);
     QVERIFY(test.mapField().isEmpty());
 }
 
diff --git a/tests/auto/protobuf/basic/tst_protobuf_deserialization_repeatedtypes.cpp b/tests/auto/protobuf/basic/tst_protobuf_deserialization_repeatedtypes.cpp
index 3497e766..229667d1 100644
--- a/tests/auto/protobuf/basic/tst_protobuf_deserialization_repeatedtypes.cpp
+++ b/tests/auto/protobuf/basic/tst_protobuf_deserialization_repeatedtypes.cpp
@@ -194,7 +194,7 @@ void QtProtobufRepeatedTypesDeserializationTest::repeatedBoolMessageTest()
 {
     RepeatedBoolMessage boolMsg;
     boolMsg.deserialize(serializer.get(), QByteArray::fromHex("0a0d01010100000000000000000001"));
-    QCOMPARE(serializer->deserializationError(), QAbstractProtobufSerializer::NoError);
+    QCOMPARE(serializer->lastError(), QAbstractProtobufSerializer::NoError);
     QtProtobuf::boolList expected{ true,  true,  true,  false, false, false, false,
                                    false, false, false, false, false, true };
     QCOMPARE(boolMsg.testRepeatedBool(), expected);
diff --git a/tests/auto/protobuf/conformance/tst_protobuf_conformance.cpp b/tests/auto/protobuf/conformance/tst_protobuf_conformance.cpp
index 50833f88..347d2122 100644
--- a/tests/auto/protobuf/conformance/tst_protobuf_conformance.cpp
+++ b/tests/auto/protobuf/conformance/tst_protobuf_conformance.cpp
@@ -116,8 +116,8 @@ QByteArray ConformaceServer::runTest(const QByteArray &reqData)
     QByteArray payload = isProtoInput ? request.protobufPayload() : request.jsonPayload().toUtf8();
 
     if (!activeDeserializer->deserialize(msg.get(), payload)
-        || activeDeserializer->deserializationError() != QAbstractProtobufSerializer::NoError) {
-        response.setParseError(activeDeserializer->deserializationErrorString());
+        || activeDeserializer->lastError() != QAbstractProtobufSerializer::NoError) {
+        response.setParseError(activeDeserializer->lastErrorString());
         return response.serialize(&m_protoSerializer);
     }
 
diff --git a/tests/auto/protobuf/json/tst_protobuf_deserialization_json_basictypes.cpp b/tests/auto/protobuf/json/tst_protobuf_deserialization_json_basictypes.cpp
index d92e371e..8b680b2a 100644
--- a/tests/auto/protobuf/json/tst_protobuf_deserialization_json_basictypes.cpp
+++ b/tests/auto/protobuf/json/tst_protobuf_deserialization_json_basictypes.cpp
@@ -527,7 +527,7 @@ void QtProtobufTypesJsonDeserializationTest::malformedJsonTest()
 
     QCOMPARE(msg.testFieldInt(), 0);
     QCOMPARE(msg.testComplexField(), SimpleStringMessage());
-    QCOMPARE(serializer->deserializationError(),
+    QCOMPARE(serializer->lastError(),
              QAbstractProtobufSerializer::UnexpectedEndOfStreamError);
 
     msg.deserialize(serializer.get(),
@@ -535,7 +535,7 @@ void QtProtobufTypesJsonDeserializationTest::malformedJsonTest()
                     "\"testComplexField\":{\"testFieldString\":\"qwerty\"}}]"_ba);
     QCOMPARE(msg.testFieldInt(), 0);
     QCOMPARE(msg.testComplexField(), SimpleStringMessage());
-    QCOMPARE(serializer->deserializationError(),
+    QCOMPARE(serializer->lastError(),
              QAbstractProtobufSerializer::InvalidFormatError);
 }
 
@@ -549,7 +549,7 @@ void QtProtobufTypesJsonDeserializationTest::invalidTypeTest()
 
     QCOMPARE(msg.testFieldInt(), -45);
     QCOMPARE(msg.testComplexField(), SimpleStringMessage());
-    QCOMPARE(serializer->deserializationError(),
+    QCOMPARE(serializer->lastError(),
              QAbstractProtobufSerializer::InvalidFormatError);
 
     // Expected integer but the value is an array
@@ -559,21 +559,21 @@ void QtProtobufTypesJsonDeserializationTest::invalidTypeTest()
 
     QCOMPARE(msg.testFieldInt(), 0);
     QCOMPARE(msg.testComplexField().testFieldString(), "qwerty"_L1);
-    QCOMPARE(serializer->deserializationError(),
+    QCOMPARE(serializer->lastError(),
              QAbstractProtobufSerializer::InvalidFormatError);
 
     SimpleIntMessage intMsg;
     intMsg.deserialize(serializer.get(), "{\"testFieldInt\": 0.5}");
-    QCOMPARE(serializer->deserializationError(), QAbstractProtobufSerializer::InvalidFormatError);
+    QCOMPARE(serializer->lastError(), QAbstractProtobufSerializer::InvalidFormatError);
     QCOMPARE(intMsg.testFieldInt(), 0);
 
     intMsg.deserialize(serializer.get(), "{\"testFieldInt\":4294967296}");
-    QCOMPARE(serializer->deserializationError(), QAbstractProtobufSerializer::InvalidFormatError);
+    QCOMPARE(serializer->lastError(), QAbstractProtobufSerializer::InvalidFormatError);
     QCOMPARE(intMsg.testFieldInt(), 0);
 
     SimpleUIntMessage uintMsg;
     uintMsg.deserialize(serializer.get(), "{\"testFieldInt\":4294967296}");
-    QCOMPARE(serializer->deserializationError(), QAbstractProtobufSerializer::InvalidFormatError);
+    QCOMPARE(serializer->lastError(), QAbstractProtobufSerializer::InvalidFormatError);
     QCOMPARE(uintMsg.testFieldInt(), 0u);
 }
 
diff --git a/tests/auto/protobuf/json/tst_protobuf_deserialization_json_enumtypes.cpp b/tests/auto/protobuf/json/tst_protobuf_deserialization_json_enumtypes.cpp
index 27dbd61f..07bd1ca1 100644
--- a/tests/auto/protobuf/json/tst_protobuf_deserialization_json_enumtypes.cpp
+++ b/tests/auto/protobuf/json/tst_protobuf_deserialization_json_enumtypes.cpp
@@ -56,7 +56,7 @@ void QtProtobufEnumTypesDeserializationTest::malformedJsonTest()
     // more braces
     test.deserialize(m_serializer.get(), "{\"localEnum\":\"LOCAL_ENUM_VALUE2\"}}");
 
-    QCOMPARE(m_serializer->deserializationError(),
+    QCOMPARE(m_serializer->lastError(),
              QAbstractProtobufSerializer::UnexpectedEndOfStreamError);
 
     RepeatedEnumMessage msg;
@@ -67,7 +67,7 @@ void QtProtobufEnumTypesDeserializationTest::malformedJsonTest()
                     "\"LOCAL_ENUM_VALUE1\",\"LOCAL_ENUM_VALUE2\","
                     "\"LOCAL_ENUM_VALUE3\"}");
 
-    QCOMPARE(m_serializer->deserializationError(),
+    QCOMPARE(m_serializer->lastError(),
              QAbstractProtobufSerializer::UnexpectedEndOfStreamError);
 }
 
@@ -76,7 +76,7 @@ void QtProtobufEnumTypesDeserializationTest::invalidTypeTest()
     // no LOCAL_ENUM_VALUE240
     SimpleEnumMessage invalidTest;
     invalidTest.deserialize(m_serializer.get(), "{\"localEnum\":\"LOCAL_ENUM_VALUE240\"}");
-    QCOMPARE(m_serializer->deserializationError(),
+    QCOMPARE(m_serializer->lastError(),
              QAbstractProtobufSerializer::InvalidFormatError);
 
     RepeatedEnumMessage msg, msg2;
@@ -86,7 +86,7 @@ void QtProtobufEnumTypesDeserializationTest::invalidTypeTest()
                     "\"LOCAL_ENUM_VALUE1\",\"LOCAL_ENUM_VALUE2\","
                     "\"LOCAL_ENUM_VALUE1\",\"LOCAL_ENUM_VALUE2\","
                     "\"LOCAL_ENUM_VALUE3\"]}");
-    QCOMPARE(m_serializer->deserializationError(),
+    QCOMPARE(m_serializer->lastError(),
              QAbstractProtobufSerializer::InvalidFormatError);
 
     // no LOCAL_ENUM_VALUE_100
@@ -95,7 +95,7 @@ void QtProtobufEnumTypesDeserializationTest::invalidTypeTest()
                      "\"LOCAL_ENUM_VALUE1\",\"LOCAL_ENUM_VALUE2\","
                      "\"LOCAL_ENUM_VALUE1\",\"LOCAL_ENUM_VALUE2\","
                      "\"LOCAL_ENUM_VALUE3\"]}");
-    QCOMPARE(m_serializer->deserializationError(),
+    QCOMPARE(m_serializer->lastError(),
              QAbstractProtobufSerializer::InvalidFormatError);
 }
 
diff --git a/tests/auto/protobuf/json/tst_protobuf_deserialization_json_maptypes.cpp b/tests/auto/protobuf/json/tst_protobuf_deserialization_json_maptypes.cpp
index 6adb6fe9..74472232 100644
--- a/tests/auto/protobuf/json/tst_protobuf_deserialization_json_maptypes.cpp
+++ b/tests/auto/protobuf/json/tst_protobuf_deserialization_json_maptypes.cpp
@@ -178,7 +178,7 @@ void QtProtobufJsonMapTypesDeserializationTest::simpleFixed32ComplexMapDeseriali
         "\"testFieldInt\":16},\"42\":{\"testComplexField\":{\"testFieldString\":"
         "\"fourty two ten sixteen\"},\"testFieldInt\":10},\"65555\":{\"testComplexField\":"
         "{\"testFieldString\":\"WUT?\"},\"testFieldInt\":10}}}"_ba);
-    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->deserializationError());
+    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->lastError());
 
     qtprotobufnamespace::tests::SimpleStringMessage stringMsg;
 
@@ -209,7 +209,7 @@ void QtProtobufJsonMapTypesDeserializationTest::boolBoolMapDeserializeTest()
 {
     BoolBoolMessageMapMessage test;
     test.deserialize(serializer.get(), "{\"mapField\":{\"true\":\"false\",\"false\":\"true\"}}");
-    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->deserializationError());
+    QCOMPARE(QAbstractProtobufSerializer::NoError, serializer->lastError());
 
     QCOMPARE(test.mapField().value(true), false);
     QCOMPARE(test.mapField().value(false), true);
@@ -223,7 +223,7 @@ void QtProtobufJsonMapTypesDeserializationTest::malformedJsonTest()
                      "{\"mapField\":{\"10\":\"ten\",\"15\":\"fifteen\",\"42\":\"fourty two\"}"_ba);
 
     QVERIFY(test.mapField().empty());
-    QCOMPARE(serializer->deserializationError(),
+    QCOMPARE(serializer->lastError(),
              QAbstractProtobufSerializer::UnexpectedEndOfStreamError);
 
     // skipped ':'
@@ -233,7 +233,7 @@ void QtProtobufJsonMapTypesDeserializationTest::malformedJsonTest()
                      "\"what is the answer?\":\"fourty two\"}}"_ba);
 
     QVERIFY(test2.mapField().empty());
-    QCOMPARE(serializer->deserializationError(),
+    QCOMPARE(serializer->lastError(),
              QAbstractProtobufSerializer::UnexpectedEndOfStreamError);
 
     SimpleFixed32StringMapMessage test3;
@@ -242,7 +242,7 @@ void QtProtobufJsonMapTypesDeserializationTest::malformedJsonTest()
                      "{\"mapField\":{\"10\":\"ten\"\"15\":\"fifteen\",\"42\":\"fourty two\"}}"_ba);
 
     QVERIFY(test3.mapField().empty());
-    QCOMPARE(serializer->deserializationError(),
+    QCOMPARE(serializer->lastError(),
              QAbstractProtobufSerializer::UnexpectedEndOfStreamError);
 }
 
@@ -254,7 +254,7 @@ void QtProtobufJsonMapTypesDeserializationTest::invalidTypeTest()
         serializer.get(),
         "{\"mapField\":{\"-10\":\"minus ten\",\"15\":\"fifteen\",\"42.3\":\"fourty two\"}}"_ba);
 
-    QCOMPARE(serializer->deserializationError(),
+    QCOMPARE(serializer->lastError(),
              QAbstractProtobufSerializer::InvalidFormatError);
 
     // -10 for uint32 is used
@@ -263,7 +263,7 @@ void QtProtobufJsonMapTypesDeserializationTest::invalidTypeTest()
                      "{\"mapField\":{\"-10\":\"ten\",\"15\":\"fifteen\",\"42\":\"fourty"
                       " two\"}}"_ba);
 
-    QCOMPARE(serializer->deserializationError(),
+    QCOMPARE(serializer->lastError(),
              QAbstractProtobufSerializer::InvalidFormatError);
 
     // expected int, but bool is used
@@ -271,7 +271,7 @@ void QtProtobufJsonMapTypesDeserializationTest::invalidTypeTest()
         serializer.get(),
         "{\"mapField\":{\"-10\":\"minus ten\",\"15\":\"fifteen\",\"false\":\"fourty two\"}}"_ba);
 
-    QCOMPARE(serializer->deserializationError(),
+    QCOMPARE(serializer->lastError(),
              QAbstractProtobufSerializer::InvalidFormatError);
 }
 
diff --git a/tests/auto/protobuf/json/tst_protobuf_deserialization_json_repeatedtypes.cpp b/tests/auto/protobuf/json/tst_protobuf_deserialization_json_repeatedtypes.cpp
index d925ace5..9260fc77 100644
--- a/tests/auto/protobuf/json/tst_protobuf_deserialization_json_repeatedtypes.cpp
+++ b/tests/auto/protobuf/json/tst_protobuf_deserialization_json_repeatedtypes.cpp
@@ -232,7 +232,7 @@ void QtProtobufRepeatedTypesJsonDeserializationTest::repeatedBoolMessageTest()
 {
     RepeatedBoolMessage boolMsg;
     boolMsg.deserialize(serializer.get(), "{\"testRepeatedBool\":[true,true,true,false,false,false,false,false,false,false,false,false,true]}"_ba);
-    QCOMPARE(serializer->deserializationError(), QAbstractProtobufSerializer::NoError);
+    QCOMPARE(serializer->lastError(), QAbstractProtobufSerializer::NoError);
     QtProtobuf::boolList expected({ true,  true,  true,  false, false, false, false,
                                     false, false, false, false, false, true });
     QCOMPARE(boolMsg.testRepeatedBool().count(), 13);
@@ -245,13 +245,13 @@ void QtProtobufRepeatedTypesJsonDeserializationTest::malformedJsonTest()
     RepeatedBoolMessage boolMsg;
     boolMsg.deserialize(serializer.get(), "{\"testRepeatedBool\":true,true,true,false,false,false,false,false,false,false,false,false,true]}"_ba);
     QVERIFY(boolMsg.testRepeatedBool().size() == 0);
-    QCOMPARE(serializer->deserializationError(), QAbstractProtobufSerializer::UnexpectedEndOfStreamError);
+    QCOMPARE(serializer->lastError(), QAbstractProtobufSerializer::UnexpectedEndOfStreamError);
 
     // twice ]
     RepeatedSInt64Message test;
     test.deserialize(serializer.get(), "{\"testRepeatedInt\":[]1,321,-65999,12324523123123,-3,3]}"_ba);
     QVERIFY(test.testRepeatedInt().size() == 0);
-    QCOMPARE(serializer->deserializationError(), QAbstractProtobufSerializer::UnexpectedEndOfStreamError);
+    QCOMPARE(serializer->lastError(), QAbstractProtobufSerializer::UnexpectedEndOfStreamError);
 
 }
 
@@ -261,14 +261,14 @@ void QtProtobufRepeatedTypesJsonDeserializationTest::invalidTypeTest()
     RepeatedSInt64Message test;
     test.deserialize(serializer.get(), "{\"testRepeatedInt\":[1,321,\"abcd\",12324523123123,-3,3]}"_ba);
     QVERIFY(test.testRepeatedInt().size() == 0);
-    QCOMPARE(serializer->deserializationError(), QAbstractProtobufSerializer::InvalidFormatError);
+    QCOMPARE(serializer->lastError(), QAbstractProtobufSerializer::InvalidFormatError);
 
     // expected bool, float is used
     RepeatedBoolMessage boolMsg;
     boolMsg.deserialize(serializer.get(),
                         "{\"testRepeatedBool\":[true,true,true,7.8,false,false,false,false,false,false,false,false,true]}"_ba);
     QVERIFY(test.testRepeatedInt().size() == 0);
-    QCOMPARE(serializer->deserializationError(), QAbstractProtobufSerializer::InvalidFormatError);
+    QCOMPARE(serializer->lastError(), QAbstractProtobufSerializer::InvalidFormatError);
 
 }
 
diff --git a/tests/auto/protobuf/wellknown/tst_protobuf_any.cpp b/tests/auto/protobuf/wellknown/tst_protobuf_any.cpp
index 9d03bf84..fc05f299 100644
--- a/tests/auto/protobuf/wellknown/tst_protobuf_any.cpp
+++ b/tests/auto/protobuf/wellknown/tst_protobuf_any.cpp
@@ -95,7 +95,7 @@ void tst_protobuf_any::anyMessage()
 
     AnyMessage message;
     message.deserialize(&serializer, input);
-    QCOMPARE_EQ(serializer.deserializationError(), QAbstractProtobufSerializer::NoError);
+    QCOMPARE_EQ(serializer.lastError(), QAbstractProtobufSerializer::NoError);
 
     std::optional<Example> opt = message.field().unpack<Example>(&serializer);
     QVERIFY(opt.has_value());
@@ -140,8 +140,8 @@ void tst_protobuf_any::repeatedAnyMessage()
     // let's try to deserialize it again
     RepeatedAnyMessage message2;
     message2.deserialize(&serializer, input);
-    if (serializer.deserializationError() != QAbstractProtobufSerializer::NoError)
-        QFAIL(qPrintable(serializer.deserializationErrorString()));
+    if (serializer.lastError() != QAbstractProtobufSerializer::NoError)
+        QFAIL(qPrintable(serializer.lastErrorString()));
     QCOMPARE_EQ(message2.anys().size(), message.anys().size());
 
     const auto anys = message.anys();