diff --git a/core/api/src/test/java/org/onlab/onos/net/provider/AbstractProviderRegistryTest.java b/core/api/src/test/java/org/onlab/onos/net/provider/AbstractProviderRegistryTest.java
index 37bee71..3ecd90d 100644
--- a/core/api/src/test/java/org/onlab/onos/net/provider/AbstractProviderRegistryTest.java
+++ b/core/api/src/test/java/org/onlab/onos/net/provider/AbstractProviderRegistryTest.java
@@ -35,7 +35,7 @@
         assertThat("provider not found", registry.getProviders().contains(fooId));
         assertEquals("incorrect provider", psFoo.provider(), pFoo);
 
-        ProviderId barId = new ProviderId("of", "bar");
+        ProviderId barId = new ProviderId("snmp", "bar");
         TestProvider pBar = new TestProvider(barId);
         TestProviderService psBar = registry.register(pBar);
         assertEquals("incorrect provider count", 2, registry.getProviders().size());
@@ -49,6 +49,16 @@
         assertThat("provider not found", registry.getProviders().contains(barId));
     }
 
+    @Test
+    public void ancillaryProviders() {
+        TestProviderRegistry registry = new TestProviderRegistry();
+        TestProvider pFoo = new TestProvider(new ProviderId("of", "foo"));
+        TestProvider pBar = new TestProvider(new ProviderId("of", "bar", true));
+        registry.register(pFoo);
+        registry.register(pBar);
+        assertEquals("incorrect provider count", 2, registry.getProviders().size());
+    }
+
     @Test(expected = IllegalStateException.class)
     public void duplicateRegistration() {
         TestProviderRegistry registry = new TestProviderRegistry();
@@ -57,6 +67,15 @@
         registry.register(pFoo);
     }
 
+    @Test(expected = IllegalStateException.class)
+    public void duplicateSchemeRegistration() {
+        TestProviderRegistry registry = new TestProviderRegistry();
+        TestProvider pFoo = new TestProvider(new ProviderId("of", "foo"));
+        TestProvider pBar = new TestProvider(new ProviderId("of", "bar"));
+        registry.register(pFoo);
+        registry.register(pBar);
+    }
+
     @Test
     public void voidUnregistration() {
         TestProviderRegistry registry = new TestProviderRegistry();