diff --git a/widget/nsBaseDragService.cpp b/widget/nsBaseDragService.cpp
index e8b62f4861a3..b23f4652c5ed 100644
--- a/widget/nsBaseDragService.cpp
+++ b/widget/nsBaseDragService.cpp
@@ -1302,11 +1302,27 @@ nsBaseDragSession::SendStoreDropTargetAndDelayEndDragSession(
 
 NS_IMETHODIMP
 nsBaseDragSession::SendDispatchToDropTargetAndResumeEndDragSession(
-    bool aShouldDrop) {
+    bool aShouldDrop, const nsTArray<RefPtr<nsIFile>>& aAllowedFiles) {
   MOZ_ASSERT(mDelayedDropBrowserParent);
+  nsTHashSet<nsString> allowedFilePaths;
+  if (aShouldDrop) {
+    for (const auto& allowedFile : aAllowedFiles) {
+      nsString filePath;
+      nsresult rv = allowedFile->GetPath(filePath);
+      if (NS_FAILED(rv)) {
+        // Something has gone wrong, cancel the drop
+        Unused << mDelayedDropBrowserParent
+                      ->SendDispatchToDropTargetAndResumeEndDragSession(
+                          false /* aShouldDrop */, nsTHashSet<nsString>());
+        mDelayedDropBrowserParent = nullptr;
+        return rv;
+      }
+      allowedFilePaths.Insert(filePath);
+    }
+  }
   Unused << mDelayedDropBrowserParent
                 ->SendDispatchToDropTargetAndResumeEndDragSession(
-                    aShouldDrop, allowedFilePaths);
+                    aShouldDrop, std::move(allowedFilePaths));
   mDelayedDropBrowserParent = nullptr;
   return NS_OK;
 }
diff --git a/widget/nsIDragSession.idl b/widget/nsIDragSession.idl
index 7bd03608b4a3..1d0228892547 100644
--- a/widget/nsIDragSession.idl
+++ b/widget/nsIDragSession.idl
@@ -26,6 +26,7 @@ class BrowserParent;
 %}
 
 interface nsIContentSecurityPolicy;
+interface nsIFile;
 
 [ptr] native BrowserParentPtr(mozilla::dom::BrowserParent);
 native EventMessage(mozilla::EventMessage);
@@ -235,7 +236,7 @@ interface nsIDragSession : nsISupports
    * @param aShouldDrop  True to send drop event, false to send dragexit event
    */
   void sendDispatchToDropTargetAndResumeEndDragSession(
-      in boolean aShouldDrop);
+      in boolean aShouldDrop, in Array<nsIFile> aAllowedFiles);
 
   /**
    * Store aElement and aDocFrame as the future drop/dragexit context, and