diff --git a/Utilities/qtsingleapplication/CMakeLists.txt b/Utilities/qtsingleapplication/CMakeLists.txt
index 515bd43c33..03ac9e230e 100644
--- a/Utilities/qtsingleapplication/CMakeLists.txt
+++ b/Utilities/qtsingleapplication/CMakeLists.txt
@@ -1,11 +1,11 @@
 if(UNIX AND DESIRED_QT_VERSION MATCHES 4)
-  set( CMAKE_CXX_FLAGS  -fPIC ${CMAKE_CXX_FLAGS} )
+  set( CMAKE_CXX_FLAGS  "-fPIC ${CMAKE_CXX_FLAGS}" )
 endif()
 
 mitk_create_module(
   PACKAGE_DEPENDS
     PUBLIC Qt4|QtGui Qt5|Widgets
     PRIVATE Qt4|QtNetwork Qt5|Network
   FORCE_STATIC
   NO_INIT
 )