--- a/build/moz.configure/toolchain.configure
+++ b/build/moz.configure/toolchain.configure
@@ -2186,7 +2186,7 @@
-@depends(target, build_environment)
+@depends(target, c_compiler, build_environment)
-def visibility_flags(target, env):
+def visibility_flags(target, c_compiler, env):
     if target.os != "WINNT":
-        if target.kernel == "Darwin":
+        if target.kernel == "Darwin" or c_compiler.type == "clang":
             return ("-fvisibility=hidden", "-fvisibility-inlines-hidden")
         return (
             "-I%s/system_wrappers" % os.path.join(env.dist),