diff --git a/src/storage.ts b/src/storage.ts
index a40d1b1bb..75c6b9b8e 100644
--- a/src/storage.ts
+++ b/src/storage.ts
@@ -665,8 +665,12 @@ export class Storage extends Service {
 
     options = Object.assign({}, options, {apiEndpoint});
 
-    // Note: EMULATOR_HOST is an experimental configuration variable. Use apiEndpoint instead.
-    const baseUrl = EMULATOR_HOST || `${options.apiEndpoint}/storage/v1`;
+    // Note: EMULATOR_HOST, if present and not overridden, has been applied to
+    // `options` at this point. Also, this uses string concatenation because the
+    // endpoint may contain a base path, and any trailing slash on that will
+    // have been removed, so using the two-arg URL constructor for relative path
+    // resolution won't work.
+    const baseUrl = new URL(options.apiEndpoint + '/storage/v1').href;
 
     const config = {
       apiEndpoint: options.apiEndpoint!,
diff --git a/test/index.ts b/test/index.ts
index 56d08e3db..08befeefc 100644
--- a/test/index.ts
+++ b/test/index.ts
@@ -437,27 +437,33 @@ describe('Storage', () => {
         delete process.env.STORAGE_EMULATOR_HOST;
       });
 
-      it('should set baseUrl to env var STORAGE_EMULATOR_HOST', () => {
+      it('should set baseUrl to env var STORAGE_EMULATOR_HOST plus standard path', () => {
         const storage = new Storage({
           projectId: PROJECT_ID,
         });
 
         const calledWith = storage.calledWith_[0];
-        assert.strictEqual(calledWith.baseUrl, EMULATOR_HOST);
+        assert.strictEqual(calledWith.baseUrl, EMULATOR_HOST + '/storage/v1');
         assert.strictEqual(
           calledWith.apiEndpoint,
           'https://internal.benchmark.com/path'
         );
       });
 
-      it('should be overriden by apiEndpoint', () => {
+      it('should be overridden by apiEndpoint', () => {
         const storage = new Storage({
           projectId: PROJECT_ID,
           apiEndpoint: 'https://some.api.com',
         });
 
         const calledWith = storage.calledWith_[0];
-        assert.strictEqual(calledWith.baseUrl, EMULATOR_HOST);
+        // NOTE: this used to assert partially the opposite of what the test
+        // says: it checked that baseUrl was _not_ overridden, but apiEndpoint
+        // was.
+        assert.strictEqual(
+          calledWith.baseUrl,
+          'https://some.api.com/storage/v1'
+        );
         assert.strictEqual(calledWith.apiEndpoint, 'https://some.api.com');
       });
 
@@ -470,7 +476,13 @@ describe('Storage', () => {
         });
 
         const calledWith = storage.calledWith_[0];
-        assert.strictEqual(calledWith.baseUrl, EMULATOR_HOST);
+        // NOTE: this used to assert partially the opposite of what the test
+        // says: it checked that baseUrl was _not_ overridden, but apiEndpoint
+        // was.
+        assert.strictEqual(
+          calledWith.baseUrl,
+          'https://internal.benchmark.com/path/storage/v1'
+        );
         assert.strictEqual(
           calledWith.apiEndpoint,
           'https://internal.benchmark.com/path'