diff --git a/src/plugins/imageformats/mng/mng.pro b/src/plugins/imageformats/mng/mng.pro
index 63926f41edd5dff263a0ee577e6adbd79fa86715..9890c11f95663852ad4ef251a1d2d68711e6d831 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 2cbb878b863187fcbc8cd38723dd9c2a7963ad1a..242ded595c854fbe21f45d1d8151facf7fd63a3e 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 cc9f93bdfe8cc587d8d7845380af2f8e9e3006da..66eea8c0107d2558f76265662df79a368bf645d7 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 7579f9c4366030dadea95892f12a4b2a435699d5..488a46bc2a9ddd2b55497a4fe469528debfc0ae3 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