diff --git a/src/test/java/org/elasticsearch/bwcompat/BasicBackwardsCompatibilityTest.java b/src/test/java/org/elasticsearch/bwcompat/BasicBackwardsCompatibilityTest.java
index e88e4d22c36..c50a9bd8ee4 100644
--- a/src/test/java/org/elasticsearch/bwcompat/BasicBackwardsCompatibilityTest.java
+++ b/src/test/java/org/elasticsearch/bwcompat/BasicBackwardsCompatibilityTest.java
@@ -22,6 +22,7 @@ import com.carrotsearch.randomizedtesting.generators.RandomPicks;
 import org.apache.lucene.index.Fields;
 import org.apache.lucene.util.English;
 import org.elasticsearch.ElasticsearchIllegalArgumentException;
+import org.elasticsearch.ExceptionsHelper;
 import org.elasticsearch.Version;
 import org.elasticsearch.action.admin.cluster.health.ClusterHealthStatus;
 import org.elasticsearch.action.admin.indices.alias.Alias;
@@ -396,7 +397,7 @@ public class BasicBackwardsCompatibilityTest extends ElasticsearchBackwardsCompa
                     .addMapping("type", mapping));
         } catch (MapperParsingException ex) {
             assertThat(ex.getCause(), instanceOf(ElasticsearchIllegalArgumentException.class));
-            assertThat(ex.getCause().getMessage(), equalTo("type=_field_names is not supported on indices created before version 1.3.0 is your cluster running multiple datanode versions?"));
+            assertThat(ExceptionsHelper.detailedMessage(ex).contains("type=_field_names is not supported on indices created before version 1.3.0"), equalTo(true));
         }
 
     }