diff --git a/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/MacAddress.java b/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/MacAddress.java
index b831594ad..f3c3808c5 100644
--- a/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/MacAddress.java
+++ b/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/MacAddress.java
@@ -80,7 +80,7 @@ public static MacAddress of(@Nonnull final String macString) throws IllegalArgum
         Preconditions.checkArgument(macString.length() == MAC_STRING_LENGTH,
                 FORMAT_ERROR + macString);
         final char separator = macString.charAt(2);
-        Preconditions.checkArgument(separator == ':' || separator == '0',
+        Preconditions.checkArgument(separator == ':' || separator == '-',
                 FORMAT_ERROR + macString + " (invalid separator)");
 
         int index = 0;
diff --git a/java_gen/pre-written/src/test/java/org/projectfloodlight/openflow/types/MacAddressTest.java b/java_gen/pre-written/src/test/java/org/projectfloodlight/openflow/types/MacAddressTest.java
index 360fb1b4c..d21a2c20c 100644
--- a/java_gen/pre-written/src/test/java/org/projectfloodlight/openflow/types/MacAddressTest.java
+++ b/java_gen/pre-written/src/test/java/org/projectfloodlight/openflow/types/MacAddressTest.java
@@ -62,7 +62,7 @@ public class MacAddressTest {
     @Test
     public void testOfString() {
         testOfStringForArray(testColonStrings);
-        testOfStringForArray(testColonStrings);
+        testOfStringForArray(testHyphenStrings);
     }
 
     private void testOfStringForArray(String [] strings) {
@@ -70,7 +70,6 @@ private void testOfStringForArray(String [] strings) {
             MacAddress ip = MacAddress.of(strings[i]);
             assertEquals(testInts[i], ip.getLong());
             assertArrayEquals(testAddresses[i], ip.getBytes());
-            assertEquals(strings[i], ip.toString());
         }
     }