diff --git a/hapi-fhir-jpaserver-subscription/src/main/java/ca/uhn/fhir/jpa/subscription/module/cache/ActiveSubscriptionCache.java b/hapi-fhir-jpaserver-subscription/src/main/java/ca/uhn/fhir/jpa/subscription/module/cache/ActiveSubscriptionCache.java
index b65bf6f5da3..e19bd4cb94a 100644
--- a/hapi-fhir-jpaserver-subscription/src/main/java/ca/uhn/fhir/jpa/subscription/module/cache/ActiveSubscriptionCache.java
+++ b/hapi-fhir-jpaserver-subscription/src/main/java/ca/uhn/fhir/jpa/subscription/module/cache/ActiveSubscriptionCache.java
@@ -20,16 +20,11 @@ package ca.uhn.fhir.jpa.subscription.module.cache;
  * #L%
  */
 
-import com.google.common.collect.Multimap;
-import com.google.common.collect.MultimapBuilder;
 import org.apache.commons.lang3.Validate;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.Map;
+import java.util.*;
 import java.util.concurrent.ConcurrentHashMap;
 
 class ActiveSubscriptionCache {
@@ -65,7 +60,8 @@ class ActiveSubscriptionCache {
 		return activeSubscription;
 	}
 
-	public void unregisterAllSubscriptionsNotInCollection(Collection<String> theAllIds) {
+	List<String> markAllSubscriptionsNotInCollectionForDeletionAndReturnIdsToDelete(Collection<String> theAllIds) {
+		List<String> retval = new ArrayList<>();
 		for (String next : new ArrayList<>(myCache.keySet())) {
 			ActiveSubscription activeSubscription = myCache.get(next);
 			if (theAllIds.contains(next)) {
@@ -74,11 +70,12 @@ class ActiveSubscriptionCache {
 			} else {
 				if (activeSubscription.isFlagForDeletion()) {
 					ourLog.info("Unregistering Subscription/{}", next);
-					remove(next);
+					retval.add(next);
 				} else {
 					activeSubscription.setFlagForDeletion(true);
 				}
 			}
 		}
+		return retval;
 	}
 }
diff --git a/hapi-fhir-jpaserver-subscription/src/main/java/ca/uhn/fhir/jpa/subscription/module/cache/SubscriptionRegistry.java b/hapi-fhir-jpaserver-subscription/src/main/java/ca/uhn/fhir/jpa/subscription/module/cache/SubscriptionRegistry.java
index 6121045b059..64a67011eb3 100644
--- a/hapi-fhir-jpaserver-subscription/src/main/java/ca/uhn/fhir/jpa/subscription/module/cache/SubscriptionRegistry.java
+++ b/hapi-fhir-jpaserver-subscription/src/main/java/ca/uhn/fhir/jpa/subscription/module/cache/SubscriptionRegistry.java
@@ -36,6 +36,7 @@ import org.springframework.stereotype.Component;
 import javax.annotation.PreDestroy;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.List;
 import java.util.Optional;
 
 /**
@@ -104,12 +105,11 @@ public class SubscriptionRegistry {
 		return canonicalized;
 	}
 
-	public void unregisterSubscription(IIdType theId) {
-		Validate.notNull(theId);
-		String subscriptionId = theId.getIdPart();
+	public void unregisterSubscription(String theSubscriptionId) {
+		Validate.notNull(theSubscriptionId);
 
-		ourLog.info("Unregistering active subscription {}", theId.toUnqualified().getValue());
-		ActiveSubscription activeSubscription = myActiveSubscriptionCache.remove(subscriptionId);
+		ourLog.info("Unregistering active subscription {}", theSubscriptionId);
+		ActiveSubscription activeSubscription = myActiveSubscriptionCache.remove(theSubscriptionId);
 		if (activeSubscription != null) {
 			mySubscriptionChannelRegistry.remove(activeSubscription);
 		}
@@ -124,7 +124,11 @@ public class SubscriptionRegistry {
 	}
 
 	void unregisterAllSubscriptionsNotInCollection(Collection<String> theAllIds) {
-		myActiveSubscriptionCache.unregisterAllSubscriptionsNotInCollection(theAllIds);
+
+		List<String> idsToDelete = myActiveSubscriptionCache.markAllSubscriptionsNotInCollectionForDeletionAndReturnIdsToDelete(theAllIds);
+		for (String id : idsToDelete) {
+			unregisterSubscription(id);
+		}
 	}
 
 	public synchronized boolean registerSubscriptionUnlessAlreadyRegistered(IBaseResource theSubscription) {
@@ -142,7 +146,7 @@ public class SubscriptionRegistry {
 				updateSubscription(theSubscription);
 				return true;
 			}
-			unregisterSubscription(theSubscription.getIdElement());
+			unregisterSubscription(theSubscription.getIdElement().getIdPart());
 		}
 		if (Subscription.SubscriptionStatus.ACTIVE.equals(newSubscription.getStatus())) {
 			registerSubscription(theSubscription.getIdElement(), theSubscription);
@@ -174,7 +178,7 @@ public class SubscriptionRegistry {
 	public boolean unregisterSubscriptionIfRegistered(IBaseResource theSubscription, String theStatusString) {
 		if (hasSubscription(theSubscription.getIdElement()).isPresent()) {
 			ourLog.info("Removing {} subscription {}", theStatusString, theSubscription.getIdElement().toUnqualified().getValue());
-			unregisterSubscription(theSubscription.getIdElement());
+			unregisterSubscription(theSubscription.getIdElement().getIdPart());
 			return true;
 		}
 		return false;
diff --git a/hapi-fhir-jpaserver-subscription/src/main/java/ca/uhn/fhir/jpa/subscription/module/channel/SubscriptionChannelRegistry.java b/hapi-fhir-jpaserver-subscription/src/main/java/ca/uhn/fhir/jpa/subscription/module/channel/SubscriptionChannelRegistry.java
index 88788d77db5..f01b41895b8 100644
--- a/hapi-fhir-jpaserver-subscription/src/main/java/ca/uhn/fhir/jpa/subscription/module/channel/SubscriptionChannelRegistry.java
+++ b/hapi-fhir-jpaserver-subscription/src/main/java/ca/uhn/fhir/jpa/subscription/module/channel/SubscriptionChannelRegistry.java
@@ -60,4 +60,8 @@ public class SubscriptionChannelRegistry {
 	public SubscriptionChannelWithHandlers get(String theChannelName) {
 		return mySubscriptionChannelCache.get(theChannelName);
 	}
+
+	public int size() {
+		return mySubscriptionChannelCache.size();
+	}
 }
diff --git a/hapi-fhir-jpaserver-subscription/src/main/java/ca/uhn/fhir/jpa/subscription/module/standalone/StandaloneSubscriptionMessageHandler.java b/hapi-fhir-jpaserver-subscription/src/main/java/ca/uhn/fhir/jpa/subscription/module/standalone/StandaloneSubscriptionMessageHandler.java
index bd5605beb4a..1d3d05ab409 100644
--- a/hapi-fhir-jpaserver-subscription/src/main/java/ca/uhn/fhir/jpa/subscription/module/standalone/StandaloneSubscriptionMessageHandler.java
+++ b/hapi-fhir-jpaserver-subscription/src/main/java/ca/uhn/fhir/jpa/subscription/module/standalone/StandaloneSubscriptionMessageHandler.java
@@ -65,7 +65,7 @@ public class StandaloneSubscriptionMessageHandler implements MessageHandler {
 		switch (theResourceModifiedMessage.getOperationType()) {
 			case DELETE:
 				if (isSubscription(theResourceModifiedMessage)) {
-					mySubscriptionRegistry.unregisterSubscription(theResourceModifiedMessage.getId(myFhirContext));
+					mySubscriptionRegistry.unregisterSubscription(theResourceModifiedMessage.getId(myFhirContext).getIdPart());
 				}
 				return;
 			case CREATE:
diff --git a/hapi-fhir-jpaserver-subscription/src/test/java/ca/uhn/fhir/jpa/subscription/module/cache/ActiveSubscriptionCacheTest.java b/hapi-fhir-jpaserver-subscription/src/test/java/ca/uhn/fhir/jpa/subscription/module/cache/ActiveSubscriptionCacheTest.java
index 9cccebca632..f9fc7af1a40 100644
--- a/hapi-fhir-jpaserver-subscription/src/test/java/ca/uhn/fhir/jpa/subscription/module/cache/ActiveSubscriptionCacheTest.java
+++ b/hapi-fhir-jpaserver-subscription/src/test/java/ca/uhn/fhir/jpa/subscription/module/cache/ActiveSubscriptionCacheTest.java
@@ -5,6 +5,7 @@ import org.junit.Test;
 import java.util.ArrayList;
 import java.util.List;
 
+import static org.hamcrest.Matchers.containsInAnyOrder;
 import static org.junit.Assert.*;
 
 public class ActiveSubscriptionCacheTest {
@@ -17,12 +18,13 @@ public class ActiveSubscriptionCacheTest {
 		assertFalse(activeSub1.isFlagForDeletion());
 		List<String> saveIds = new ArrayList<>();
 
-		activeSubscriptionCache.unregisterAllSubscriptionsNotInCollection(saveIds);
+		List<String> idsToDelete = activeSubscriptionCache.markAllSubscriptionsNotInCollectionForDeletionAndReturnIdsToDelete(saveIds);
 		assertTrue(activeSub1.isFlagForDeletion());
 		assertNotNull(activeSubscriptionCache.get(id1));
+		assertEquals(0, idsToDelete.size());
 
-		activeSubscriptionCache.unregisterAllSubscriptionsNotInCollection(saveIds);
-		assertNull(activeSubscriptionCache.get(id1));
+		idsToDelete = activeSubscriptionCache.markAllSubscriptionsNotInCollectionForDeletionAndReturnIdsToDelete(saveIds);
+		assertThat(idsToDelete, containsInAnyOrder(id1));
 	}
 
 	@Test
@@ -35,14 +37,15 @@ public class ActiveSubscriptionCacheTest {
 
 		assertFalse(activeSub1.isFlagForDeletion());
 
-		activeSubscriptionCache.unregisterAllSubscriptionsNotInCollection(saveIds);
+		List<String> idsToDelete = activeSubscriptionCache.markAllSubscriptionsNotInCollectionForDeletionAndReturnIdsToDelete(saveIds);
 		assertTrue(activeSub1.isFlagForDeletion());
 		assertNotNull(activeSubscriptionCache.get(id1));
+		assertEquals(0, idsToDelete.size());
 
 		saveIds.add(id1);
-		activeSubscriptionCache.unregisterAllSubscriptionsNotInCollection(saveIds);
+		idsToDelete = activeSubscriptionCache.markAllSubscriptionsNotInCollectionForDeletionAndReturnIdsToDelete(saveIds);
 		assertFalse(activeSub1.isFlagForDeletion());
-		assertNotNull(activeSubscriptionCache.get(id1));
+		assertEquals(0, idsToDelete.size());
 	}
 
 	@Test
@@ -58,9 +61,9 @@ public class ActiveSubscriptionCacheTest {
 		activeSub1.setFlagForDeletion(true);
 		List<String> saveIds = new ArrayList<>();
 
-		activeSubscriptionCache.unregisterAllSubscriptionsNotInCollection(saveIds);
+		List<String> idsToDelete = activeSubscriptionCache.markAllSubscriptionsNotInCollectionForDeletionAndReturnIdsToDelete(saveIds);
 
-		assertNull(activeSubscriptionCache.get(id1));
+		assertThat(idsToDelete, containsInAnyOrder(id1));
 		assertNotNull(activeSubscriptionCache.get(id2));
 		assertTrue(activeSub2.isFlagForDeletion());
 	}
@@ -80,7 +83,7 @@ public class ActiveSubscriptionCacheTest {
 		saveIds.add(id1);
 		saveIds.add(id2);
 
-		activeSubscriptionCache.unregisterAllSubscriptionsNotInCollection(saveIds);
+		activeSubscriptionCache.markAllSubscriptionsNotInCollectionForDeletionAndReturnIdsToDelete(saveIds);
 
 		assertNotNull(activeSubscriptionCache.get(id1));
 		assertFalse(activeSub1.isFlagForDeletion());