diff --git a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowEventHandler.java b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowEventHandler.java
index 3a3faee..f49b10a 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowEventHandler.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowEventHandler.java
@@ -143,8 +143,7 @@
     /**
      * Run the thread.
      */
-    @SuppressWarnings("unchecked")
-	@Override
+    @Override
     public void run() {
 	startup();
 
@@ -341,8 +340,9 @@
 		    }
 		    modifiedFlowPaths.put(flowPath.flowId().value(), flowPath);
 		    break;
-		default:
-			break;
+		case FP_TYPE_UNKNOWN:
+		    log.error("FlowPath event with unknown type");
+		    break;
 		}
 		allFlowPaths.put(flowPath.flowId().value(), flowPath);
 
diff --git a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowManager.java b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowManager.java
index fd65520..bd498cc 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowManager.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowManager.java
@@ -404,8 +404,9 @@
 	    case FE_USER_DELETE:
 		datagridService.notificationSendFlowEntryRemoved(flowEntry.flowEntryId());
 		break;
-		default:
-			break;
+	    case FE_USER_UNKNOWN:
+		assert(false);
+		break;
 	    }
 	}
     }
diff --git a/src/main/java/net/onrc/onos/ofcontroller/topology/Topology.java b/src/main/java/net/onrc/onos/ofcontroller/topology/Topology.java
index f356991..fc75591 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/topology/Topology.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/topology/Topology.java
@@ -265,9 +265,9 @@
 
 	    break;
 	}
-	default:
-		// unexpected case
-		break;
+	case ELEMENT_UNKNOWN:
+	    // TODO: Adding "assert(false);" here can be dangerous
+	    break;
 	}
 
 	return isModified;
@@ -318,9 +318,9 @@
 	    }
 	    break;
 	}
-	default:
-		// unexpected case
-		break;
+	case ELEMENT_UNKNOWN:
+	    // TODO: Adding "assert(false);" here can be dangerous
+	    break;
 	}
 
 	return isModified;
diff --git a/src/main/java/net/onrc/onos/ofcontroller/topology/TopologyElement.java b/src/main/java/net/onrc/onos/ofcontroller/topology/TopologyElement.java
index c70d42c..0fefa3a 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/topology/TopologyElement.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/topology/TopologyElement.java
@@ -162,10 +162,12 @@
 	    return "Link=" +
 		Long.toHexString(fromSwitchDpid) + "/" + fromSwitchPort + "/" +
 		Long.toHexString(toSwitchDpid) + "/" + toSwitchPort;
-	default:
-		assert(false);
-		return null;
+	case ELEMENT_UNKNOWN:
+	    return "Element=UNKNOWN";
 	}
+
+	assert(false);
+	return null;
     }
 
     /**
diff --git a/src/main/java/net/onrc/onos/ofcontroller/topology/TopologyManager.java b/src/main/java/net/onrc/onos/ofcontroller/topology/TopologyManager.java
index 26e6e12..02e0ffb 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/topology/TopologyManager.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/topology/TopologyManager.java
@@ -225,11 +225,15 @@
 	    SwitchPort dest = flowPath.dataPath().dstPort();
 	    return ShortestPath.getTopologyShortestPath(topology, src, dest);
 	}
+
 	case FP_TYPE_EXPLICIT_PATH:
 	    return flowPath.dataPath();
-	default:
-		return null;
+
+	case FP_TYPE_UNKNOWN:
+	    return null;
 	}
+
+	return null;
     }
 
     /**