diff --git a/src/test/validation.test.ts b/src/test/validation.test.ts
index 55c0618d..de4e73f5 100644
--- a/src/test/validation.test.ts
+++ b/src/test/validation.test.ts
@@ -72,6 +72,7 @@ describe('validateVersion', () => {
 		assert.throws(() => validateVersion('.0.1'));
 		assert.throws(() => validateVersion('0.1.'));
 		assert.throws(() => validateVersion('0.0.0.1'));
+		assert.throws(() => validateVersion('1.0.a'));
 	});
 });