diff --git a/gcp-region/main.test.ts b/gcp-region/main.test.ts
index 8b419d1..51a3601 100644
--- a/gcp-region/main.test.ts
+++ b/gcp-region/main.test.ts
@@ -23,4 +23,22 @@ describe("gcp-region", async () => {
     });
     expect(state.outputs.value.value).toBe("asia-east1-a");
   });
+
+  it("gpu only invalid default", async () => {
+    const state = await runTerraformApply(import.meta.dir, {
+      regions: '["us-west2"]',
+      default: "us-west2-a",
+      gpu_only: "true",
+    });
+    expect(state.outputs.value.value).toBe("");
+  });
+
+  it("gpu only valid default", async () => {
+    const state = await runTerraformApply(import.meta.dir, {
+      regions: '["us-west2"]',
+      default: "us-west2-b",
+      gpu_only: "true",
+    });
+    expect(state.outputs.value.value).toBe("us-west2-b");
+  });
 });