diff --git a/mozilla/widget/src/windows/nsDragService.cpp b/mozilla/widget/src/windows/nsDragService.cpp
index 69851a7912c..b12e055b344 100644
--- a/mozilla/widget/src/windows/nsDragService.cpp
+++ b/mozilla/widget/src/windows/nsDragService.cpp
@@ -222,6 +222,12 @@ nsDragService::InvokeDragSession(nsIDOMNode *aDOMNode,
   if (NS_FAILED(rv))
     return rv;
 
+  // set the directory promise flavour
+  // if this fails it won't affect the drag so we can just continue
+  trans->SetTransferData(kFilePromiseDirectoryMime,
+                         dropLocalFile,
+                         sizeof(nsILocalFile*));
+
   // Create a new FileURI to pass to the nsIDownload
   nsCOMPtr<nsIURI> targetURI;
 
diff --git a/mozilla/widget/src/windows/nsDragService.h b/mozilla/widget/src/windows/nsDragService.h
index 2c9d760c458..b94fd142747 100644
--- a/mozilla/widget/src/windows/nsDragService.h
+++ b/mozilla/widget/src/windows/nsDragService.h
@@ -63,14 +63,14 @@ typedef struct {
 #endif // SHCNE_RENAMEITEM_DEF
 
 // Register for shell notifications func ptr
-typedef ULONG (*SHCNRegPtr)(HWND hWnd,                      // Ordinal of 2
-                            int fSources,
-                            LONG fEvents,
-                            UINT wMsg,
-                            int cEntries,
-                            SHChangeNotifyStruct *pschn);
+typedef WINSHELLAPI ULONG (WINAPI *SHCNRegPtr)(HWND hWnd,                      // Ordinal of 2
+                                               int fSources,
+                                               LONG fEvents,
+                                               UINT wMsg,
+                                               int cEntries,
+                                               SHChangeNotifyStruct *pschn);
 // Unregister form from the shell notifications func ptr
-typedef BOOL (*SHCNDeregPtr)(ULONG ulID);                   // Ordinal of 4
+typedef WINSHELLAPI BOOL (WINAPI *SHCNDeregPtr)(ULONG ulID);                   // Ordinal of 4
 
 /**
  * Native Win32 DragService wrapper