diff --git a/rebar.config b/rebar.config
index e805dba..3d725b6 100644
--- a/rebar.config
+++ b/rebar.config
@@ -7,8 +7,10 @@
 ]}.
 
 {port_env, [
-    {".*", "CFLAGS", "$CFLAGS -g -Wall -Werror -O3 -fno-strict-aliasing"},
-    {".*", "CXXFLAGS", "$CXXFLAGS -g -Wall -Werror -O3"},
+    {"(linux|solaris|freebsd|netbsd|openbsd|dragonfly|darwin)",
+        "CFLAGS", "$CFLAGS -g -Wall -Werror -O3 -fno-strict-aliasing"},
+    {"(linux|solaris|freebsd|netbsd|openbsd|dragonfly|darwin)",
+        "CXXFLAGS", "$CXXFLAGS -g -Wall -Werror -O3"},
 
     {"(linux|solaris|freebsd|netbsd|openbsd|dragonfly|darwin)",
         "LDFLAGS", "$LDFLAGS -lstdc++"},