diff --git a/CHANGELOG b/CHANGELOG
index 1df0ff5..4d9e3df 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Ensure Ajax.Response#getHeader returns null for missing headers in Opera. [Tobie Langel]
+
 * Allow WEBrick to simulate slow or dropped connections and to ease Ajax request inspection. [Tobie Langel]
 
 * Ensure Ajax.Response#getHeader returns null for missing headers. [Tobie Langel]
diff --git a/src/ajax.js b/src/ajax.js
index 90c4a83..e576a1e 100644
--- a/src/ajax.js
+++ b/src/ajax.js
@@ -209,8 +209,7 @@ Ajax.Request = Class.create(Ajax.Base, {
   
   getHeader: function(name) {
     try {
-      var header = this.transport.getResponseHeader(name);
-      return Object.isUndefined(header) ? null : header;
+      return this.transport.getResponseHeader(name) || null;
     } catch (e) { return null }
   },