diff --git a/rust/bindgen_test.go b/rust/bindgen_test.go
index 12cdb3c..0ba0ff8 100644
--- a/rust/bindgen_test.go
+++ b/rust/bindgen_test.go
@@ -115,7 +115,7 @@
 	ctx := testRust(t, `
 		rust_bindgen {
 			name: "libbindgen_cstd",
-			wrapper_src: "src/any.h",
+			wrapper_src: "src/any.hpp",
 			crate_name: "bindgen",
 			stem: "libbindgen",
 			source_stem: "bindings",
@@ -141,6 +141,16 @@
 	if !strings.Contains(libbindgen_cppstd.Args["cflags"], "-std=foo") {
 		t.Errorf("cpp_std value not passed in to rust_bindgen as a clang flag")
 	}
+
+	// Make sure specifying cpp_std emits the '-x c++' flag
+	if !strings.Contains(libbindgen_cppstd.Args["cflags"], "-x c++") {
+		t.Errorf("Setting cpp_std should cause the '-x c++' flag to be emitted")
+	}
+
+	// Make sure specifying c_std omits the '-x c++' flag
+	if strings.Contains(libbindgen_cstd.Args["cflags"], "-x c++") {
+		t.Errorf("Setting c_std should not cause the '-x c++' flag to be emitted")
+	}
 }
 
 func TestBindgenDisallowedFlags(t *testing.T) {