diff --git a/dom/crypto/KeyAlgorithm.h b/dom/crypto/KeyAlgorithm.h
index 3b3c4ce18082..4900685ef555 100644
--- a/dom/crypto/KeyAlgorithm.h
+++ b/dom/crypto/KeyAlgorithm.h
@@ -31,12 +31,6 @@ enum KeyAlgorithmStructuredCloneTags {
 
 }
 
-template<>
-struct HasDangerousPublicDestructor<dom::KeyAlgorithm>
-{
-  static const bool value = true;
-};
-
 namespace dom {
 
 class KeyAlgorithm : public nsISupports,
@@ -49,8 +43,6 @@ public:
 public:
   KeyAlgorithm(nsIGlobalObject* aGlobal, const nsString& aName);
 
-  virtual ~KeyAlgorithm();
-
   nsIGlobalObject* GetParentObject() const
   {
     return mGlobal;
@@ -72,6 +64,8 @@ public:
   }
 
 protected:
+  virtual ~KeyAlgorithm();
+
   nsRefPtr<nsIGlobalObject> mGlobal;
   nsString mName;
   CK_MECHANISM_TYPE mMechanism;
diff --git a/dom/crypto/WebCryptoTask.cpp b/dom/crypto/WebCryptoTask.cpp
index 8272b972c9d9..a99434348fb7 100644
--- a/dom/crypto/WebCryptoTask.cpp
+++ b/dom/crypto/WebCryptoTask.cpp
@@ -1167,8 +1167,8 @@ public:
       if (params.mLength.WasPassed()) {
         mLength = params.mLength.Value();
       } else {
-        KeyAlgorithm hashAlg(global, hashName);
-        switch (hashAlg.Mechanism()) {
+        nsRefPtr<KeyAlgorithm> hashAlg = new KeyAlgorithm(global, hashName);
+        switch (hashAlg->Mechanism()) {
           case CKM_SHA_1:
           case CKM_SHA256:
             mLength = 512;