diff --git a/driver-core/src/main/com/mongodb/operation/IndexHelper.java b/driver-core/src/main/com/mongodb/operation/IndexHelper.java
index 6d1f726..abf342e 100644
--- a/driver-core/src/main/com/mongodb/operation/IndexHelper.java
+++ b/driver-core/src/main/com/mongodb/operation/IndexHelper.java
@@ -17,7 +17,7 @@
 package com.mongodb.operation;

 import org.bson.BsonDocument;
-import org.bson.BsonInt32;
+import org.bson.BsonNumber;
 import org.bson.BsonString;
 import org.bson.BsonValue;

@@ -35,9 +35,11 @@ final class IndexHelper {
                 indexName.append('_');
             }
             indexName.append(keyNames).append('_');
+
             BsonValue ascOrDescValue = index.get(keyNames);
-            if (ascOrDescValue instanceof BsonInt32) {
-                indexName.append(((BsonInt32) ascOrDescValue).getValue());
+
+            if (ascOrDescValue instanceof BsonNumber) {
+                indexName.append(((BsonNumber) ascOrDescValue).intValue());
             } else if (ascOrDescValue instanceof BsonString) {
                 indexName.append(((BsonString) ascOrDescValue).getValue().replace(' ', '_'));
             }