diff --git a/dom/xhr/XMLHttpRequestMainThread.cpp b/dom/xhr/XMLHttpRequestMainThread.cpp
index 8a1c1f0ada..a1afb90417 100644
--- a/dom/xhr/XMLHttpRequestMainThread.cpp
+++ b/dom/xhr/XMLHttpRequestMainThread.cpp
@@ -86,6 +86,7 @@
 #include "mozilla/Preferences.h"
 #include "private/pprio.h"
 #include "XMLHttpRequestUpload.h"
+#include "nsHostObjectProtocolHandler.h"
 
 using namespace mozilla::net;
 
@@ -2880,6 +2881,11 @@ XMLHttpRequestMainThread::SendInternal(const RequestBodyBase* aBody)
     return NS_ERROR_DOM_NETWORK_ERR;
   }
 
+  // non-GET requests aren't allowed for blob.
+  if (IsBlobURI(mRequestURL) && !mRequestMethod.EqualsLiteral("GET")) {
+    return NS_ERROR_DOM_NETWORK_ERR;
+  }
+
   PopulateNetworkInterfaceId();
 
   // XXX We should probably send a warning to the JS console