diff --git a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/PerformanceMonitor.java b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/PerformanceMonitor.java
index 5a1df0f..293b426 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/PerformanceMonitor.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/PerformanceMonitor.java
@@ -146,7 +146,7 @@
 	 */
 	public String toString() {
 	    double milli = elapsed() / Math.pow(10, 6);
-	    return Double.toString(milli) + "ms";
+	    return Double.toString(milli) + " ms";
 	}
     }