diff --git a/libgambatte/SConstruct b/libgambatte/SConstruct
index e882514..87e1eaa 100644
--- a/libgambatte/SConstruct
+++ b/libgambatte/SConstruct
@@ -5,7 +5,9 @@ vars = Variables()
 vars.Add('CC')
 vars.Add('CXX')
 
-env = Environment(CPPPATH = ['src', 'include', '../common'],
+import os
+env = Environment(ENV = os.environ,
+                  CPPPATH = ['src', 'include', '../common'],
                   CFLAGS = global_cflags + global_defines,
                   CXXFLAGS = global_cxxflags + global_defines,
                   variables = vars)