diff --git a/dom/base/Link.cpp b/dom/base/Link.cpp
index 0d7e70a57b0a..fe91eb6cb1ed 100644
--- a/dom/base/Link.cpp
+++ b/dom/base/Link.cpp
@@ -613,7 +613,7 @@ void
 Link::CreateSearchParamsIfNeeded()
 {
   if (!mSearchParams) {
-    mSearchParams = new URLSearchParams(this, this);
+    mSearchParams = new URLSearchParams(this);
     UpdateURLSearchParams();
   }
 }
diff --git a/dom/base/URL.cpp b/dom/base/URL.cpp
index 2eb0aff1f73f..5e4d46313074 100644
--- a/dom/base/URL.cpp
+++ b/dom/base/URL.cpp
@@ -533,7 +533,7 @@ void
 URL::CreateSearchParamsIfNeeded()
 {
   if (!mSearchParams) {
-    mSearchParams = new URLSearchParams(this, this);
+    mSearchParams = new URLSearchParams(this);
     UpdateURLSearchParams();
   }
 }
diff --git a/dom/base/URLSearchParams.cpp b/dom/base/URLSearchParams.cpp
index 9c8991067448..84e0d7e0f695 100644
--- a/dom/base/URLSearchParams.cpp
+++ b/dom/base/URLSearchParams.cpp
@@ -293,7 +293,7 @@ URLParams::Serialize(nsAString& aValue) const
   }
 }
 
-NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(URLSearchParams, mParent, mObserver)
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(URLSearchParams, mObserver)
 NS_IMPL_CYCLE_COLLECTING_ADDREF(URLSearchParams)
 NS_IMPL_CYCLE_COLLECTING_RELEASE(URLSearchParams)
 
@@ -302,19 +302,13 @@ NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(URLSearchParams)
   NS_INTERFACE_MAP_ENTRY(nsISupports)
 NS_INTERFACE_MAP_END
 
-URLSearchParams::URLSearchParams(nsISupports* aParent,
-                                 URLSearchParamsObserver* aObserver)
-  : mParams(new URLParams())
-  , mParent(aParent)
-  , mObserver(aObserver)
+URLSearchParams::URLSearchParams(URLSearchParamsObserver* aObserver)
+  : mParams(new URLParams()), mObserver(aObserver)
 {
 }
 
-URLSearchParams::URLSearchParams(nsISupports* aParent,
-                                 const URLSearchParams& aOther)
-  : mParams(new URLParams(*aOther.mParams.get()))
-  , mParent(aParent)
-  , mObserver(aOther.mObserver)
+URLSearchParams::URLSearchParams(const URLSearchParams& aOther)
+  : mParams(new URLParams(*aOther.mParams.get())), mObserver(aOther.mObserver)
 {
 }
 
@@ -334,10 +328,8 @@ URLSearchParams::Constructor(const GlobalObject& aGlobal,
                              const nsAString& aInit,
                              ErrorResult& aRv)
 {
-  nsRefPtr<URLSearchParams> sp =
-    new URLSearchParams(aGlobal.GetAsSupports(), nullptr);
+  nsRefPtr<URLSearchParams> sp = new URLSearchParams(nullptr);
   sp->ParseInput(NS_ConvertUTF16toUTF8(aInit));
-
   return sp.forget();
 }
 
@@ -346,9 +338,7 @@ URLSearchParams::Constructor(const GlobalObject& aGlobal,
                              URLSearchParams& aInit,
                              ErrorResult& aRv)
 {
-  nsRefPtr<URLSearchParams> sp =
-    new URLSearchParams(aGlobal.GetAsSupports(), aInit);
-
+  nsRefPtr<URLSearchParams> sp = new URLSearchParams(aInit);
   return sp.forget();
 }
 
diff --git a/dom/base/URLSearchParams.h b/dom/base/URLSearchParams.h
index f60461faef1a..f32a02d471fe 100644
--- a/dom/base/URLSearchParams.h
+++ b/dom/base/URLSearchParams.h
@@ -114,16 +114,14 @@ public:
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(URLSearchParams)
 
-  URLSearchParams(nsISupports* aParent,
-                  URLSearchParamsObserver* aObserver);
+  explicit URLSearchParams(URLSearchParamsObserver* aObserver);
 
-  URLSearchParams(nsISupports* aParent,
-                  const URLSearchParams& aOther);
+  explicit URLSearchParams(const URLSearchParams& aOther);
 
   // WebIDL methods
   nsISupports* GetParentObject() const
   {
-    return mParent;
+    return nullptr;
   }
 
   virtual JSObject*
@@ -176,7 +174,6 @@ private:
   void NotifyObserver();
 
   UniquePtr<URLParams> mParams;
-  nsCOMPtr<nsISupports> mParent;
   nsRefPtr<URLSearchParamsObserver> mObserver;
 };
 
diff --git a/dom/fetch/Fetch.cpp b/dom/fetch/Fetch.cpp
index 216f40d2cb79..e61d0339593d 100644
--- a/dom/fetch/Fetch.cpp
+++ b/dom/fetch/Fetch.cpp
@@ -1543,12 +1543,12 @@ FetchBody<Derived>::ContinueConsumeBody(nsresult aStatus, uint32_t aResultLength
         }
 
         if (isValidUrlEncodedMimeType) {
-          URLParams params;
-          params.ParseInput(data);
+          nsRefPtr<URLSearchParams> params = new URLSearchParams(nullptr);
+          params->ParseInput(data);
 
           nsRefPtr<nsFormData> fd = new nsFormData(DerivedClass()->GetParentObject());
           FillFormIterator iterator(fd);
-          DebugOnly<bool> status = params.ForEach(iterator);
+          DebugOnly<bool> status = params->ForEach(iterator);
           MOZ_ASSERT(status);
 
           localPromise->MaybeResolve(fd);
diff --git a/dom/workers/URL.cpp b/dom/workers/URL.cpp
index 9dccd72de5df..b0bb9f2394aa 100644
--- a/dom/workers/URL.cpp
+++ b/dom/workers/URL.cpp
@@ -952,7 +952,7 @@ void
 URL::CreateSearchParamsIfNeeded()
 {
   if (!mSearchParams) {
-    mSearchParams = new URLSearchParams(this, this);
+    mSearchParams = new URLSearchParams(this);
     UpdateURLSearchParams();
   }
 }
diff --git a/toolkit/components/places/tests/cpp/mock_Link.h b/toolkit/components/places/tests/cpp/mock_Link.h
index a5e641c8c59f..42a94c530088 100644
--- a/toolkit/components/places/tests/cpp/mock_Link.h
+++ b/toolkit/components/places/tests/cpp/mock_Link.h
@@ -145,8 +145,7 @@ NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(URLSearchParams)
 NS_INTERFACE_MAP_END
 
 
-URLSearchParams::URLSearchParams(nsISupports* aParent,
-                                 URLSearchParamsObserver* aObserver)
+URLSearchParams::URLSearchParams(URLSearchParamsObserver* aObserver)
 {
 }