diff --git a/modules/elasticsearch/src/main/java/org/elasticsearch/cluster/metadata/MetaData.java b/modules/elasticsearch/src/main/java/org/elasticsearch/cluster/metadata/MetaData.java
index 9726e8a3239..cd74e48b641 100644
--- a/modules/elasticsearch/src/main/java/org/elasticsearch/cluster/metadata/MetaData.java
+++ b/modules/elasticsearch/src/main/java/org/elasticsearch/cluster/metadata/MetaData.java
@@ -50,7 +50,7 @@ import java.util.regex.Pattern;
 
 import static org.elasticsearch.common.collect.Lists.*;
 import static org.elasticsearch.common.collect.MapBuilder.*;
-import static org.elasticsearch.common.collect.Maps.newHashMap;
+import static org.elasticsearch.common.collect.Maps.*;
 import static org.elasticsearch.common.collect.Sets.*;
 import static org.elasticsearch.common.settings.ImmutableSettings.*;
 
@@ -231,7 +231,7 @@ public class MetaData implements Iterable<IndexMetaData> {
             return routing;
         }
         if (indexAliases.size() > 1) {
-            throw new ElasticSearchIllegalArgumentException("Alias [" + aliasOrIndex + "] has more than one indices associated with it [" + indexAliases.keySet() + "], can't execute a single index op");
+            throw new ElasticSearchIllegalArgumentException("Alias [" + aliasOrIndex + "] has more than one index associated with it [" + indexAliases.keySet() + "], can't execute a single index op");
         }
         AliasMetaData aliasMd = indexAliases.values().iterator().next();
         if (aliasMd.indexRouting() != null) {
@@ -239,7 +239,7 @@ public class MetaData implements Iterable<IndexMetaData> {
                 if (routing.equals(aliasMd.indexRouting())) {
                     return routing;
                 } else {
-                    return null;
+                    throw new ElasticSearchIllegalArgumentException("Alias [" + aliasOrIndex + "] has index routing associated with it [" + aliasMd.indexRouting() + "], and was provided with routing value [" + routing + "], rejecting operation");
                 }
             }
             return aliasMd.indexRouting();
diff --git a/modules/test/integration/src/test/java/org/elasticsearch/test/integration/routing/AliasResolveRoutingTests.java b/modules/test/integration/src/test/java/org/elasticsearch/test/integration/routing/AliasResolveRoutingTests.java
index 87287b856f2..9561e058b20 100644
--- a/modules/test/integration/src/test/java/org/elasticsearch/test/integration/routing/AliasResolveRoutingTests.java
+++ b/modules/test/integration/src/test/java/org/elasticsearch/test/integration/routing/AliasResolveRoutingTests.java
@@ -30,12 +30,11 @@ import org.testng.annotations.Test;
 
 import java.util.Map;
 import java.util.Set;
-import java.util.regex.Matcher;
 
-import static org.elasticsearch.cluster.metadata.AliasAction.newAddAliasAction;
-import static org.elasticsearch.common.collect.Maps.newHashMap;
-import static org.elasticsearch.common.collect.Sets.newHashSet;
-import static org.hamcrest.MatcherAssert.assertThat;
+import static org.elasticsearch.cluster.metadata.AliasAction.*;
+import static org.elasticsearch.common.collect.Maps.*;
+import static org.elasticsearch.common.collect.Sets.*;
+import static org.hamcrest.MatcherAssert.*;
 import static org.hamcrest.Matchers.*;
 
 /**
@@ -92,7 +91,11 @@ public class AliasResolveRoutingTests extends AbstractNodesTests {
         assertThat(clusterService.state().metaData().resolveIndexRouting(null, "alias21"), equalTo("1"));
         assertThat(clusterService.state().metaData().resolveIndexRouting("3", "test1"), equalTo("3"));
         assertThat(clusterService.state().metaData().resolveIndexRouting("0", "alias10"), equalTo("0"));
-        assertThat(clusterService.state().metaData().resolveIndexRouting("1", "alias10"), nullValue());
+        try {
+            clusterService.state().metaData().resolveIndexRouting("1", "alias10");
+        } catch (ElasticSearchIllegalArgumentException e) {
+            // all is well, we can't have two mappings, one provided, and one in the alias
+        }
 
         try {
             clusterService.state().metaData().resolveIndexRouting(null, "alias0");