diff --git a/CMakeLists.txt b/CMakeLists.txt
index 692f4e1..6b8729c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -59,8 +59,8 @@ add_definitions(
 )
 
 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 ########################