diff --git a/dom/base/nsScriptLoader.cpp b/dom/base/nsScriptLoader.cpp
index de2726ca5367..0ac40117da39 100644
--- a/dom/base/nsScriptLoader.cpp
+++ b/dom/base/nsScriptLoader.cpp
@@ -1030,7 +1030,7 @@ nsScriptLoader::StartFetchingModuleAndDependencies(nsModuleLoadRequest* aRequest
 
   RefPtr<GenericPromise> ready = childRequest->mReady.Ensure(__func__);
 
-  nsresult rv = StartLoad(childRequest, false);
+  nsresult rv = StartLoad(childRequest);
   if (NS_FAILED(rv)) {
     childRequest->mReady.Reject(rv, __func__);
     return ready;
@@ -1178,7 +1178,7 @@ nsScriptLoader::InstantiateModuleTree(nsModuleLoadRequest* aRequest)
 }
 
 nsresult
-nsScriptLoader::StartLoad(nsScriptLoadRequest *aRequest, bool aScriptFromHead)
+nsScriptLoader::StartLoad(nsScriptLoadRequest *aRequest)
 {
   MOZ_ASSERT(aRequest->IsLoading());
   NS_ENSURE_TRUE(mDocument, NS_ERROR_NULL_POINTER);
@@ -1251,7 +1251,7 @@ nsScriptLoader::StartLoad(nsScriptLoadRequest *aRequest, bool aScriptFromHead)
   nsCOMPtr<nsIClassOfService> cos(do_QueryInterface(channel));
 
   if (cos) {
-    if (aScriptFromHead &&
+    if (aRequest->mScriptFromHead &&
         !(script && (script->GetScriptAsync() || script->GetScriptDeferred()))) {
       // synchronous head scripts block loading of most other non js/css
       // content such as images
@@ -1535,10 +1535,10 @@ nsScriptLoader::ProcessScriptElement(nsIScriptElement *aElement)
       request->mURI = scriptURI;
       request->mIsInline = false;
       request->mReferrerPolicy = ourRefPolicy;
+      // keep request->mScriptFromHead to false so we don't treat non preloaded
+      // scripts as blockers for full page load. See bug 792438.
 
-      // set aScriptFromHead to false so we don't treat non preloaded scripts as
-      // blockers for full page load. See bug 792438.
-      rv = StartLoad(request, false);
+      rv = StartLoad(request);
       if (NS_FAILED(rv)) {
         // Asynchronously report the load failure
         NS_DispatchToCurrentThread(
@@ -2805,8 +2805,9 @@ nsScriptLoader::PreloadURI(nsIURI *aURI, const nsAString &aCharset,
   request->mURI = aURI;
   request->mIsInline = false;
   request->mReferrerPolicy = aReferrerPolicy;
+  request->mScriptFromHead = aScriptFromHead;
 
-  nsresult rv = StartLoad(request, aScriptFromHead);
+  nsresult rv = StartLoad(request);
   if (NS_FAILED(rv)) {
     return;
   }
diff --git a/dom/base/nsScriptLoader.h b/dom/base/nsScriptLoader.h
index a0a7f08daaaf..16b3be94c014 100644
--- a/dom/base/nsScriptLoader.h
+++ b/dom/base/nsScriptLoader.h
@@ -74,6 +74,7 @@ public:
                       const mozilla::dom::SRIMetadata &aIntegrity)
     : mKind(aKind),
       mElement(aElement),
+      mScriptFromHead(false),
       mProgress(Progress::Loading),
       mIsInline(true),
       mHasSourceMapURL(false),
@@ -167,6 +168,7 @@ public:
 
   const nsScriptKind mKind;
   nsCOMPtr<nsIScriptElement> mElement;
+  bool mScriptFromHead;   // Synchronous head script block loading of other non js/css content.
   Progress mProgress;     // Are we still waiting for a load to complete?
   bool mIsInline;         // Is the script inline or loaded?
   bool mHasSourceMapURL;  // Does the HTTP header have a source map url?
@@ -519,7 +521,7 @@ private:
   /**
    * Start a load for aRequest's URI.
    */
-  nsresult StartLoad(nsScriptLoadRequest *aRequest, bool aScriptFromHead);
+  nsresult StartLoad(nsScriptLoadRequest *aRequest);
 
   /**
    * Process any pending requests asynchronously (i.e. off an event) if there