diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5e6abd6c3..fa3159344 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -118,7 +118,7 @@ endif (WITH_RAWZOR)
 
 find_package(OpenMP)
 if (OPENMP_FOUND)
-	set(CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS} ${OpenMP_CXX_FLAGS})
+	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OpenMP_CXX_FLAGS}")
 endif (OPENMP_FOUND)
 
 add_subdirectory (rtexif)