diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0bfae31..03af652 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -55,8 +55,8 @@ include( ConfigureChecks.cmake )
 ###### global compiler settings #################
 
 set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${TQT_CXX_FLAGS}" )
-set( CMAKE_SHARED_LINKER_FLAGS "-Wl,--no-undefined" )
-set( CMAKE_MODULE_LINKER_FLAGS "-Wl,--no-undefined" )
+set( CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,--no-undefined" )
+set( CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -Wl,--no-undefined" )
 
 
 ##### source directories ########################