--- a/accessible/src/msaa/nsTextAccessibleWrap.cpp
+++ b/accessible/src/msaa/nsTextAccessibleWrap.cpp
@@ -271,18 +271,18 @@ STDMETHODIMP nsTextAccessibleWrap::get_f
   }
 
   nsCOMPtr<nsIDeviceContext> deviceContext;
   rc->GetDeviceContext(*getter_AddRefs(deviceContext));
   if (!deviceContext) {
     return E_FAIL;
   }
 
-  nsIFontMetrics *fm;
-  rc->GetFontMetrics(fm);
+  nsCOMPtr<nsIFontMetrics> fm;
+  rc->GetFontMetrics(*getter_AddRefs(fm));
   if (!fm) {
     return E_FAIL;
   }
 
   nsAutoString fontFamily;
   deviceContext->FirstExistingFont(fm->Font(), fontFamily);
   if (fontFamily.IsEmpty())
     return S_FALSE;