diff --git a/SConstruct b/SConstruct
index ff3e6a934..1e869c77f 100644
--- a/SConstruct
+++ b/SConstruct
@@ -1657,11 +1657,12 @@ if not preconfigured:
         ndebug_defines = ['-DNDEBUG']
 
         # c++11 support / https://github.com/mapnik/mapnik/issues/1683
-        #  - workaround boost gil channel_algorithm.hpp narrowing error
         #  - upgrade to PHOENIX_V3 since that is needed for c++11 compile
         if 'c++11' in env['CUSTOM_CXXFLAGS']:
-            env.Append(CXXFLAGS = '-Wno-c++11-narrowing')
             env.Append(CPPDEFINES = '-DBOOST_SPIRIT_USE_PHOENIX_V3=1')
+            #  - workaround boost gil channel_algorithm.hpp narrowing error
+            if 'clang++' in env['CXX']:
+                env.Append(CXXFLAGS = '-Wno-c++11-narrowing')
 
         # Enable logging in debug mode (always) and release mode (when specified)
         if env['DEFAULT_LOG_SEVERITY']: