diff --git a/content/xbl/src/nsXBLBinding.cpp b/content/xbl/src/nsXBLBinding.cpp
index f4bec243a0d..7e5a3c6d4a4 100644
--- a/content/xbl/src/nsXBLBinding.cpp
+++ b/content/xbl/src/nsXBLBinding.cpp
@@ -425,6 +425,8 @@ nsXBLBinding::InstallEventHandlers(nsIContent* aBoundElement)
             receiver->AddEventListener(type, (nsIDOMMouseListener*)handler, useCapture);
           else
             receiver->AddEventListener(type, (nsIDOMKeyListener*)handler, useCapture);
+
+          NS_RELEASE(handler);
         }
       
         // XXX Call AddScriptEventListener for other IID types
diff --git a/layout/xbl/src/nsXBLBinding.cpp b/layout/xbl/src/nsXBLBinding.cpp
index f4bec243a0d..7e5a3c6d4a4 100644
--- a/layout/xbl/src/nsXBLBinding.cpp
+++ b/layout/xbl/src/nsXBLBinding.cpp
@@ -425,6 +425,8 @@ nsXBLBinding::InstallEventHandlers(nsIContent* aBoundElement)
             receiver->AddEventListener(type, (nsIDOMMouseListener*)handler, useCapture);
           else
             receiver->AddEventListener(type, (nsIDOMKeyListener*)handler, useCapture);
+
+          NS_RELEASE(handler);
         }
       
         // XXX Call AddScriptEventListener for other IID types