diff --git a/src/plugins/imageformats/mng/mng.pro b/src/plugins/imageformats/mng/mng.pro
index 63926f41..9890c11f 100644
--- a/src/plugins/imageformats/mng/mng.pro
+++ b/src/plugins/imageformats/mng/mng.pro
@@ -1,6 +1,7 @@
 TARGET  = qmng
 
 PLUGIN_TYPE = imageformats
+PLUGIN_CLASS_NAME = QMngPlugin
 load(qt_plugin)
 
 HEADERS += qmnghandler_p.h
diff --git a/src/plugins/imageformats/tga/tga.pro b/src/plugins/imageformats/tga/tga.pro
index 2cbb878b..242ded59 100644
--- a/src/plugins/imageformats/tga/tga.pro
+++ b/src/plugins/imageformats/tga/tga.pro
@@ -1,6 +1,7 @@
 TARGET = qtga
 
 PLUGIN_TYPE = imageformats
+PLUGIN_CLASS_NAME = QTgaPlugin
 load(qt_plugin)
 
 HEADERS += qtgahandler.h \
diff --git a/src/plugins/imageformats/tiff/tiff.pro b/src/plugins/imageformats/tiff/tiff.pro
index cc9f93bd..66eea8c0 100644
--- a/src/plugins/imageformats/tiff/tiff.pro
+++ b/src/plugins/imageformats/tiff/tiff.pro
@@ -1,6 +1,7 @@
 TARGET  = qtiff
 
 PLUGIN_TYPE = imageformats
+PLUGIN_CLASS_NAME = QTiffPlugin
 load(qt_plugin)
 
 HEADERS += qtiffhandler_p.h
diff --git a/src/plugins/imageformats/wbmp/wbmp.pro b/src/plugins/imageformats/wbmp/wbmp.pro
index 7579f9c4..488a46bc 100644
--- a/src/plugins/imageformats/wbmp/wbmp.pro
+++ b/src/plugins/imageformats/wbmp/wbmp.pro
@@ -1,6 +1,7 @@
 TARGET = qwbmp
 
 PLUGIN_TYPE = imageformats
+PLUGIN_CLASS_NAME = QWbmpPlugin
 load(qt_plugin)
 
 HEADERS += qwbmphandler_p.h