diff --git a/CMakeLists.txt b/CMakeLists.txt
index 93e27d450..a32346889 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -6,7 +6,9 @@ SUBDIRS(Source Modules Templates)
 INCLUDE (${CMAKE_ROOT}/Modules/Dart.cmake)
 
 # use the ansi CXX compile flag for building cmake
-SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${CMAKE_ANSI_CXXFLAGS}")  
+IF (CMAKE_ANSI_CXXFLAGS)
+  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${CMAKE_ANSI_CXXFLAGS}")  
+ENDIF (CMAKE_ANSI_CXXFLAGS)
 # add some testing dependencies
 IF(BUILD_TESTING)
   IF (DART_ROOT)
diff --git a/Tests/Complex/CMakeLists.txt b/Tests/Complex/CMakeLists.txt
index 3b06b8411..83f78748a 100644
--- a/Tests/Complex/CMakeLists.txt
+++ b/Tests/Complex/CMakeLists.txt
@@ -2,7 +2,9 @@
 PROJECT (Complex)
 
 # use the ansi CXX compile flag for building cmake
-SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${CMAKE_ANSI_CXXFLAGS}")  
+IF (CMAKE_ANSI_CXXFLAGS)
+  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${CMAKE_ANSI_CXXFLAGS}")  
+ENDIF (CMAKE_ANSI_CXXFLAGS)
 
 ADD_DEFINITIONS(-DCMAKE_IS_FUN)
 SUBDIRS(Library Executable)
diff --git a/Tests/ComplexOneConfig/CMakeLists.txt b/Tests/ComplexOneConfig/CMakeLists.txt
index 3b06b8411..83f78748a 100644
--- a/Tests/ComplexOneConfig/CMakeLists.txt
+++ b/Tests/ComplexOneConfig/CMakeLists.txt
@@ -2,7 +2,9 @@
 PROJECT (Complex)
 
 # use the ansi CXX compile flag for building cmake
-SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${CMAKE_ANSI_CXXFLAGS}")  
+IF (CMAKE_ANSI_CXXFLAGS)
+  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${CMAKE_ANSI_CXXFLAGS}")  
+ENDIF (CMAKE_ANSI_CXXFLAGS)
 
 ADD_DEFINITIONS(-DCMAKE_IS_FUN)
 SUBDIRS(Library Executable)
diff --git a/Tests/ComplexRelativePaths/CMakeLists.txt b/Tests/ComplexRelativePaths/CMakeLists.txt
index 3b06b8411..83f78748a 100644
--- a/Tests/ComplexRelativePaths/CMakeLists.txt
+++ b/Tests/ComplexRelativePaths/CMakeLists.txt
@@ -2,7 +2,9 @@
 PROJECT (Complex)
 
 # use the ansi CXX compile flag for building cmake
-SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${CMAKE_ANSI_CXXFLAGS}")  
+IF (CMAKE_ANSI_CXXFLAGS)
+  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${CMAKE_ANSI_CXXFLAGS}")  
+ENDIF (CMAKE_ANSI_CXXFLAGS)
 
 ADD_DEFINITIONS(-DCMAKE_IS_FUN)
 SUBDIRS(Library Executable)