diff --git a/java_gen/pre-written/src/test/java/org/projectfloodlight/openflow/types/IPAddressTest.java b/java_gen/pre-written/src/test/java/org/projectfloodlight/openflow/types/IPAddressTest.java
new file mode 100644
index 0000000..25fc943
--- /dev/null
+++ b/java_gen/pre-written/src/test/java/org/projectfloodlight/openflow/types/IPAddressTest.java
@@ -0,0 +1,54 @@
+package org.projectfloodlight.openflow.types;
+
+import static org.junit.Assert.*;
+
+import org.junit.Test;
+
+/**
+ * Most tests are in IPv4AddressTest and IPv6AddressTest
+ * Just exception testing here
+ * @author gregor
+ *
+ */
+public class IPAddressTest {
+    @Test
+    public void testOfException() {
+        try {
+            IPAddress.of("Foobar");
+            fail("Should have thrown IllegalArgumentException");
+        } catch (IllegalArgumentException e) {
+            // expected
+        }
+        try {
+            IPAddressWithMask.of("Foobar");
+            fail("Should have thrown IllegalArgumentException");
+        } catch (IllegalArgumentException e) {
+            // expected
+        }
+        try {
+            IPAddress.of(null);
+            fail("Should have thrown NullPointerException");
+        } catch (NullPointerException e) {
+            assertNotNull(e.getMessage());
+        }
+        try {
+            IPAddressWithMask.of(null);
+            fail("Should have thrown NullPointerException");
+        } catch (NullPointerException e) {
+            assertNotNull(e.getMessage());
+        }
+        try {
+            IPAddress.of(null);
+            fail("Should have thrown NullPointerException");
+        } catch (NullPointerException e) {
+            assertNotNull(e.getMessage());
+        }
+        try {
+            IPAddressWithMask.of(null);
+            fail("Should have thrown NullPointerException");
+        } catch (NullPointerException e) {
+            assertNotNull(e.getMessage());
+        }
+    }
+
+}