diff --git a/src/protobuf/QtProtobufProperties.cmake.in b/src/protobuf/QtProtobufProperties.cmake.in
index 8fcd48e7..a51f0466 100644
--- a/src/protobuf/QtProtobufProperties.cmake.in
+++ b/src/protobuf/QtProtobufProperties.cmake.in
@@ -11,5 +11,28 @@ if(NOT QT_NO_CREATE_TARGETS)
                 QT_PROTO_INCLUDES "${CMAKE_STAGING_PREFIX}/${proto_include_dir}")
         endif()
     endforeach()
+
+    foreach(proto_include_dir IN LISTS _@target@_proto_external_include_dirs)
+        if(NOT IS_ABSOLUTE "${proto_include_dir}")
+            if(NOT QT_NO_WARN_PROTOBUF_BROKEN_INCLUDES)
+                message(WRANING "The protobuf include directory ${proto_include_dir} must be an"
+                    " absolute path. Skipping adding it to the @target@ module QT_PROTO_INCLUDES."
+                    " Use QT_NO_WARN_PROTOBUF_BROKEN_INCLUDES to suppress this warning.")
+            endif()
+            continue()
+        endif()
+        if(NOT EXISTS "${proto_include_dir}")
+            if(NOT QT_NO_WARN_PROTOBUF_BROKEN_INCLUDES)
+                message(WARNING "The protobuf include directory ${proto_include_dir} doesn't exist."
+                    " Skipping adding it to the @target@ module QT_PROTO_INCLUDES."
+                    " Use QT_NO_WARN_PROTOBUF_BROKEN_INCLUDES to suppress this warning.")
+            endif()
+            continue()
+        endif()
+
+        set_property(TARGET ${QT_CMAKE_EXPORT_NAMESPACE}::@target@ APPEND PROPERTY
+            QT_PROTO_INCLUDES "${proto_include_dir}")
+    endforeach()
+
     unset(_@target@_proto_include_dirs)
 endif()