diff --git a/xml/src/main/java/org/springframework/xml/namespace/SimpleNamespaceContext.java b/xml/src/main/java/org/springframework/xml/namespace/SimpleNamespaceContext.java
index 6e0ec943..1f15e3d0 100644
--- a/xml/src/main/java/org/springframework/xml/namespace/SimpleNamespaceContext.java
+++ b/xml/src/main/java/org/springframework/xml/namespace/SimpleNamespaceContext.java
@@ -1,11 +1,11 @@
 /*
- * Copyright 2005-2010 the original author or authors.
+ * Copyright 2005-2012 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
- *      http://www.apache.org/licenses/LICENSE-2.0
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
@@ -151,9 +151,11 @@ public class SimpleNamespaceContext implements NamespaceContext {
      * @param prefix the prefix to be removed
      */
     public void removeBinding(String prefix) {
-        String namespaceUri = prefixToNamespaceUri.get(prefix);
-        Set<String> prefixes = getPrefixesInternal(namespaceUri);
-        prefixes.remove(prefix);
+        String namespaceUri = prefixToNamespaceUri.remove(prefix);
+        if (namespaceUri != null) {
+            Set<String> prefixes = getPrefixesInternal(namespaceUri);
+            prefixes.remove(prefix);
+        }
     }
 
     public boolean hasBinding(String prefix) {