diff --git a/dom/serviceworkers/ServiceWorkerScriptCache.cpp b/dom/serviceworkers/ServiceWorkerScriptCache.cpp
index 00b69ebf45a0..239a50f553b0 100644
--- a/dom/serviceworkers/ServiceWorkerScriptCache.cpp
+++ b/dom/serviceworkers/ServiceWorkerScriptCache.cpp
@@ -693,6 +693,16 @@ nsresult CompareNetwork::Initialize(nsIPrincipal* aPrincipal,
     return rv;
   }
 
+  // Set the IsInThirdPartyContext for the channel's loadInfo according to the
+  // partitionKey of the principal. The worker is foreign if it's using
+  // partitioned principal, i.e. the partitionKey is not empty. In this case,
+  // we need to set the bit to the channel's loadInfo.
+  if (!aPrincipal->OriginAttributesRef().mPartitionKey.IsEmpty()) {
+    nsCOMPtr<nsILoadInfo> loadInfo = mChannel->LoadInfo();
+    rv = loadInfo->SetIsInThirdPartyContext(true);
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+  }
+
   nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(mChannel);
   if (httpChannel) {
     // Spec says no redirects allowed for top-level SW scripts.
diff --git a/dom/workers/ScriptLoader.cpp b/dom/workers/ScriptLoader.cpp
index b841a6e35719..f2e00a173a69 100644
--- a/dom/workers/ScriptLoader.cpp
+++ b/dom/workers/ScriptLoader.cpp
@@ -1025,6 +1025,18 @@ nsresult WorkerScriptLoader::LoadScript(
     if (NS_WARN_IF(NS_FAILED(rv))) {
       return rv;
     }
+
+    // Set the IsInThirdPartyContext for the channel's loadInfo according to the
+    // partitionKey of the principal. The worker is foreign if it's using
+    // partitioned principal, i.e. the partitionKey is not empty. In this case,
+    // we need to set the bit to the channel's loadInfo.
+    if (!principal->OriginAttributesRef().mPartitionKey.IsEmpty()) {
+      nsCOMPtr<nsILoadInfo> loadInfo = channel->LoadInfo();
+      rv = loadInfo->SetIsInThirdPartyContext(true);
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return rv;
+      }
+    }
   }
 
   // Associate any originating stack with the channel.