googleapis
diff --git a/...va/gax/src/main/java/com/google/api/gax/rpc/internal/QuotaProjectIdHidingCredentials.java b/...va/gax/src/main/java/com/google/api/gax/rpc/internal/QuotaProjectIdHidingCredentials.java
@@ -89,4 +89,9 @@ public boolean hasRequestMetadataOnly() {
   public void refresh() throws IOException {
     this.wrappedCredentials.refresh();
   }
+
+  @Override
+  public String getUniverseDomain() throws IOException {
+    return this.wrappedCredentials.getUniverseDomain();
+  }
 }
diff --git a/...ax/src/test/java/com/google/api/gax/rpc/internal/QuotaProjectIdHidingCredentialsTest.java b/...ax/src/test/java/com/google/api/gax/rpc/internal/QuotaProjectIdHidingCredentialsTest.java
@@ -101,4 +101,15 @@ void quotaProjectIdHidingCredentials_getAuthenticationType() throws IOException
 
     Mockito.verify(credentials, Mockito.atLeastOnce()).refresh();
   }
+
+  @Test
+  void quotaProjectIdHidingCredentials_getUniverseDomain() throws IOException {
+    Credentials credentials = Mockito.mock(GoogleCredentials.class);
+    Mockito.when(credentials.getUniverseDomain()).thenReturn("example.com");
+
+    QuotaProjectIdHidingCredentials quotaProjectIdHidingCredentials =
+        new QuotaProjectIdHidingCredentials(credentials);
+
+    assertEquals(quotaProjectIdHidingCredentials.getUniverseDomain(), "example.com");
+  }
 }
diff --git a/showcase/gapic-showcase/src/test/java/com/google/showcase/v1beta1/it/ITEndpointContext.java b/showcase/gapic-showcase/src/test/java/com/google/showcase/v1beta1/it/ITEndpointContext.java
@@ -444,4 +444,23 @@ void endpointResolution_builderBuilderBackToBuilder() throws IOException {
     echoStubSettingsBuilder = echoStubSettings.toBuilder();
     Truth.assertThat(echoStubSettingsBuilder.getEndpoint()).isEqualTo(customEndpoint);
   }
+
+  @Test
+  void universeDomainValidation_quotaProjectId_credentialsNonGDUMatchesUserConfiguration()
+      throws IOException {
+    String universeDomain = "random.com";
+    EchoSettings echoSettings =
+        ExtendedEchoSettings.newBuilder()
+            .setQuotaProjectId("exampleProject")
+            .setCredentialsProvider(UniverseDomainCredentialsProvider.create(universeDomain))
+            .setEndpoint(TestClientInitializer.DEFAULT_GRPC_ENDPOINT)
+            .setUniverseDomain(universeDomain)
+            .setTransportChannelProvider(
+                EchoSettings.defaultGrpcTransportProviderBuilder()
+                    .setChannelConfigurator(ManagedChannelBuilder::usePlaintext)
+                    .build())
+            .build();
+    echoClient = EchoClient.create(echoSettings);
+    Truth.assertThat(echoClient.echo(DEFAULT_REQUEST).getContent()).isEqualTo("echo");
+  }
 }