diff --git a/CMakeLists.txt b/CMakeLists.txt
index ce2bfd0d4..3628b77e1 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -22,6 +22,8 @@ add_subdirectory( ui )
 add_subdirectory( shell )
 add_subdirectory( generators )
 
+add_definitions (-DQT3_SUPPORT -DQT3_SUPPORT_WARNINGS)
+
 include_directories(
    ${CMAKE_SOURCE_DIR}/okular/ui/painter_agg2/
 )
diff --git a/generators/chm/CMakeLists.txt b/generators/chm/CMakeLists.txt
index dd1d7f5a4..a417a7f10 100644
--- a/generators/chm/CMakeLists.txt
+++ b/generators/chm/CMakeLists.txt
@@ -1,5 +1,7 @@
 add_subdirectory( kio-msits )
 
+add_definitions (-DQT3_SUPPORT -DQT3_SUPPORT_WARNINGS)
+
 include_directories(
    ${CMAKE_SOURCE_DIR}/okular
    ${CMAKE_BINARY_DIR}/okular
diff --git a/generators/dvi/CMakeLists.txt b/generators/dvi/CMakeLists.txt
index af53f0995..e7b28c924 100644
--- a/generators/dvi/CMakeLists.txt
+++ b/generators/dvi/CMakeLists.txt
@@ -3,6 +3,7 @@ include_directories(
    ${CMAKE_BINARY_DIR}/okular
 )
 
+add_definitions (-DQT3_SUPPORT -DQT3_SUPPORT_WARNINGS)
 #add_definitions(-DDEBUG_DVIRENDERER -DDEBUG_RENDER -DDEBUG_PRESCAN)
 
 ########### next target ###############
diff --git a/generators/ghostview/CMakeLists.txt b/generators/ghostview/CMakeLists.txt
index 65c66ca2d..cc421b5f6 100644
--- a/generators/ghostview/CMakeLists.txt
+++ b/generators/ghostview/CMakeLists.txt
@@ -6,6 +6,7 @@ include_directories(
    ${CMAKE_SOURCE_DIR}/libqgs
 )
 
+add_definitions (-DQT3_SUPPORT -DQT3_SUPPORT_WARNINGS)
 add_definitions(${KDE4_ENABLE_EXCEPTIONS})
 
 ########### next target ###############