diff --git a/pom.xml b/pom.xml
index 133e294..3e9dc4c 100644
--- a/pom.xml
+++ b/pom.xml
@@ -236,12 +236,12 @@
     <dependency>
       <groupId>org.codehaus.jackson</groupId>
       <artifactId>jackson-core-asl</artifactId>
-      <version>1.9.11</version>
+      <version>1.9.13</version>
     </dependency>
     <dependency>
       <groupId>org.codehaus.jackson</groupId>
       <artifactId>jackson-mapper-asl</artifactId>
-      <version>1.9.11</version>
+      <version>1.9.13</version>
     </dependency>
     <dependency>
       <groupId>ch.qos.logback</groupId>
@@ -283,9 +283,9 @@
       <version>4.1.21</version>
     </dependency>
     <dependency>
-      <groupId>org.jboss.netty</groupId>
-      <artifactId>netty</artifactId>
-      <version>3.2.6.Final</version>
+      <groupId>io.netty</groupId>
+      <artifactId>netty-all</artifactId>
+      <version>4.0.8.Final</version>
     </dependency>
     <dependency>
       <groupId>args4j</groupId>
@@ -379,4 +379,4 @@
     </dependency>
     -->
   </dependencies>
-</project>
\ No newline at end of file
+</project>
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 bca9ef7..2b3b0f2 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowManager.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowManager.java
@@ -127,6 +127,10 @@
 		}
 		Map<Long, IOFSwitch> mySwitches =
 		    floodlightProvider.getSwitches();
+		if (mySwitches.isEmpty()) {
+			log.trace("No switches controlled");
+			return;
+		}
 		LinkedList<IFlowEntry> addFlowEntries =
 		    new LinkedList<IFlowEntry>();
 		LinkedList<IFlowEntry> deleteFlowEntries =
@@ -267,6 +271,10 @@
 		}
 		Map<Long, IOFSwitch> mySwitches =
 		    floodlightProvider.getSwitches();
+		if (mySwitches.isEmpty()) {
+			log.trace("No switches controlled");
+			return;
+		}
 		LinkedList<IFlowPath> deleteFlows = new LinkedList<IFlowPath>();
 
 		boolean processed_measurement_flow = false;