diff --git a/lib/OpenLayers/Ajax.js b/lib/OpenLayers/Ajax.js
index 693b1c1097..05a26b725b 100644
--- a/lib/OpenLayers/Ajax.js
+++ b/lib/OpenLayers/Ajax.js
@@ -405,7 +405,7 @@ OpenLayers.Ajax.Request = OpenLayers.Class(OpenLayers.Ajax.Base, {
                 }
             } else {
                 for (var i in extras) {
-                    headers[i] = pair[i];
+                    headers[i] = extras[i];
                 }
             }
         }