diff --git a/cc/x86_darwin_host.go b/cc/x86_darwin_host.go
index 1bd3dd0..7f4c489 100644
--- a/cc/x86_darwin_host.go
+++ b/cc/x86_darwin_host.go
@@ -63,10 +63,10 @@
 		"-Wl,-rpath,@loader_path/lib64",
 	}
 
-	darwinClangCflags = append([]string{
+	darwinClangCflags = append(clangFilterUnknownCflags(darwinCflags), []string{
 		"-integrated-as",
 		"-fstack-protector-strong",
-	}, clangFilterUnknownCflags(darwinCflags)...)
+	}...)
 
 	darwinClangLdflags = clangFilterUnknownCflags(darwinLdflags)
 
diff --git a/cc/x86_linux_host.go b/cc/x86_linux_host.go
index d1a92f1..528d2a7 100644
--- a/cc/x86_linux_host.go
+++ b/cc/x86_linux_host.go
@@ -66,28 +66,28 @@
 		`-Wl,-rpath,\$$ORIGIN/lib64`,
 	}
 
-	linuxClangCflags = append([]string{
+	linuxClangCflags = append(clangFilterUnknownCflags(linuxCflags), []string{
 		"--gcc-toolchain=${linuxGccRoot}",
 		"--sysroot=${linuxGccRoot}/sysroot",
 		"-fstack-protector-strong",
-	}, clangFilterUnknownCflags(linuxCflags)...)
+	}...)
 
-	linuxClangLdflags = append([]string{
+	linuxClangLdflags = append(clangFilterUnknownCflags(linuxLdflags), []string{
 		"--gcc-toolchain=${linuxGccRoot}",
 		"--sysroot=${linuxGccRoot}/sysroot",
-	}, clangFilterUnknownCflags(linuxLdflags)...)
+	}...)
 
-	linuxX86ClangLdflags = append([]string{
+	linuxX86ClangLdflags = append(clangFilterUnknownCflags(linuxX86Ldflags), []string{
 		"-B${linuxGccRoot}/lib/gcc/${linuxGccTriple}/${linuxGccVersion}/32",
 		"-L${linuxGccRoot}/lib/gcc/${linuxGccTriple}/${linuxGccVersion}/32",
 		"-L${linuxGccRoot}/${linuxGccTriple}/lib32",
-	}, clangFilterUnknownCflags(linuxX86Ldflags)...)
+	}...)
 
-	linuxX8664ClangLdflags = append([]string{
+	linuxX8664ClangLdflags = append(clangFilterUnknownCflags(linuxX8664Ldflags), []string{
 		"-B${linuxGccRoot}/lib/gcc/${linuxGccTriple}/${linuxGccVersion}",
 		"-L${linuxGccRoot}/lib/gcc/${linuxGccTriple}/${linuxGccVersion}",
 		"-L${linuxGccRoot}/${linuxGccTriple}/lib64",
-	}, clangFilterUnknownCflags(linuxX8664Ldflags)...)
+	}...)
 
 	linuxClangCppflags = []string{
 		"-isystem ${linuxGccRoot}/${linuxGccTriple}/include/c++/${linuxGccVersion}",