diff --git a/artio-codecs/src/test/java/uk/co/real_logic/artio/dictionary/ExampleDictionary.java b/artio-codecs/src/test/java/uk/co/real_logic/artio/dictionary/ExampleDictionary.java
index 3cb6d3f88c..579004fe2f 100644
--- a/artio-codecs/src/test/java/uk/co/real_logic/artio/dictionary/ExampleDictionary.java
+++ b/artio-codecs/src/test/java/uk/co/real_logic/artio/dictionary/ExampleDictionary.java
@@ -387,6 +387,10 @@ public final class ExampleDictionary
         "8=FIX.4.4\0019=71\00135=0\001115=abc\001116=2\001117=1.1\001127=19700101-00:00:00.001" +
         "\001120=2\001121=1\001121=2\00110=053\001";
 
+    public static final String REPEATING_GROUP_MESSAGE_WITH_THREE =
+        "8=FIX.4.4\0019=71\00135=0\001115=abc\001116=2\001117=1.1\001127=19700101-00:00:00.001" +
+        "\001120=3\001121=1\001121=1\001121=2\00110=053\001";
+
     public static final String SINGLE_REPEATING_GROUP_MESSAGE =
         "8=FIX.4.4\0019=65\00135=0\001115=abc\001116=2\001117=1.1\001127=19700101-00:00:00.001" +
         "\001120=1\001121=2\00110=052\001";
diff --git a/artio-codecs/src/test/java/uk/co/real_logic/artio/dictionary/generation/AbstractDecoderGeneratorTest.java b/artio-codecs/src/test/java/uk/co/real_logic/artio/dictionary/generation/AbstractDecoderGeneratorTest.java
index 6cb11281b4..10a80e1a32 100644
--- a/artio-codecs/src/test/java/uk/co/real_logic/artio/dictionary/generation/AbstractDecoderGeneratorTest.java
+++ b/artio-codecs/src/test/java/uk/co/real_logic/artio/dictionary/generation/AbstractDecoderGeneratorTest.java
@@ -838,6 +838,16 @@ public void shouldReasonablyValidateGroupNumbersLessThanTheNumberOfElementsInThe
         assertInvalid(decoder, INCORRECT_NUMINGROUP_COUNT_FOR_REPEATING_GROUP, 120);
     }
 
+    //TODO this test was added to guide the bugfix
+    @Test
+    public void shouldReasonablyValidateGroupNumbersLessThanTheNumberOfElementsInTheGroupList() throws Exception
+    {
+        final Decoder decoder = decodeHeartbeatWithRejectingUnknownFields(
+            REPEATING_GROUP_MESSAGE_WITH_THREE, REPEATING_GROUP_MESSAGE_WITH_TOO_HIGH_NUMBER_FIELD);
+
+//        assertInvalid(decoder, INCORRECT_NUMINGROUP_COUNT_FOR_REPEATING_GROUP, 120);
+    }
+
     @Test
     public void shouldSupportGroupNumbersGreaterThanTheNumberOfElementsInTheNestedGroup() throws Exception
     {
@@ -1879,6 +1889,16 @@ Decoder decodeHeartbeatWithoutValidation(final String example) throws Exception
         return decoder;
     }
 
+    private Decoder decodeHeartbeatWithRejectingUnknownFields(final String... example) throws Exception
+    {
+        final Decoder decoder = (Decoder)heartbeatWithRejectingUnknownFields.getConstructor().newInstance();
+        for (final String s : example)
+        {
+            decode(s, decoder);
+        }
+        return decoder;
+    }
+
     private Decoder decodeHeartbeatWithRejectingUnknownFields(final String example) throws Exception
     {
         final Decoder decoder = (Decoder)heartbeatWithRejectingUnknownFields.getConstructor().newInstance();