diff --git a/package.json b/package.json
index a4f2fe49b..698b8af09 100644
--- a/package.json
+++ b/package.json
@@ -95,6 +95,7 @@
     "@grpc/grpc-js": "^1.0.3",
     "@grpc/proto-loader": "^0.7.0",
     "@types/async-retry": "^1.4.3",
+    "@types/duplexify": "^3.6.4",
     "@types/mime": "^3.0.0",
     "@types/mocha": "^9.1.1",
     "@types/mockery": "^1.4.29",
diff --git a/src/storage.ts b/src/storage.ts
index a7027bc83..681145d3d 100644
--- a/src/storage.ts
+++ b/src/storage.ts
@@ -715,7 +715,7 @@ export class Storage extends Service {
       customEndpoint = true;
     }
 
-    if (options.apiEndpoint) {
+    if (options.apiEndpoint && options.apiEndpoint !== apiEndpoint) {
       apiEndpoint = Storage.sanitizeEndpoint(options.apiEndpoint);
       customEndpoint = true;
     }
diff --git a/test/index.ts b/test/index.ts
index 72637a466..34104d743 100644
--- a/test/index.ts
+++ b/test/index.ts
@@ -174,6 +174,30 @@ describe('Storage', () => {
       assert.strictEqual(calledWith.apiEndpoint, `${apiEndpoint}`);
     });
 
+    it('should not set `customEndpoint` if `apiEndpoint` matches default', () => {
+      const apiEndpoint = 'https://storage.googleapis.com';
+      const storage = new Storage({
+        apiEndpoint,
+      });
+
+      const calledWith = storage.calledWith_[0];
+      assert.strictEqual(calledWith.apiEndpoint, apiEndpoint);
+      assert.strictEqual(calledWith.customEndpoint, false);
+    });
+
+    it('should not set `customEndpoint` if `apiEndpoint` matches default (w/ universe domain)', () => {
+      const universeDomain = 'my.universe';
+      const apiEndpoint = `https://storage.${universeDomain}`;
+      const storage = new Storage({
+        apiEndpoint,
+        universeDomain,
+      });
+
+      const calledWith = storage.calledWith_[0];
+      assert.strictEqual(calledWith.apiEndpoint, apiEndpoint);
+      assert.strictEqual(calledWith.customEndpoint, false);
+    });
+
     it('should propagate the useAuthWithCustomEndpoint option', () => {
       const useAuthWithCustomEndpoint = true;
       const apiEndpoint = 'https://some.fake.endpoint';