diff --git a/lib/OpenLayers/Ajax.js b/lib/OpenLayers/Ajax.js
index 46599274df..a15bc0a123 100644
--- a/lib/OpenLayers/Ajax.js
+++ b/lib/OpenLayers/Ajax.js
@@ -211,6 +211,11 @@ OpenLayers.Ajax.Request.prototype = OpenLayers.Class.inherit( OpenLayers.Ajax.Ba
       var body = this.options.postBody ? this.options.postBody : parameters;
       this.transport.send(this.options.method == 'post' ? body : null);
 
+      /* Force Firefox to handle ready state 4 for synchronous requests */
+      if (!this.options.asynchronous && this.transport.overrideMimeType) {
+          this.onStateChange();
+      }
+
     } catch (e) {
       this.dispatchException(e);
     }