diff --git a/api/spotify.ts b/api/spotify.ts
index d4b6a1f..9b5ebdf 100644
--- a/api/spotify.ts
+++ b/api/spotify.ts
@@ -168,7 +168,9 @@ const getCurrentUsersPlaylistsNextPage: (
   });
 };
 
-interface GetPlaylistDetailsFirstPageArgs extends EndpointHandlerWithResArgs {
+interface GetPlaylistDetailsFirstPageArgs
+  extends Omit<EndpointHandlerWithResArgs, "res"> {
+  res?: Res;
   initialFields: string;
   playlistID: string;
 }
@@ -181,16 +183,17 @@ const getPlaylistDetailsFirstPage: (
   initialFields,
   playlistID,
 }) => {
-  return await singleRequest<GetPlaylistData>({
+  let args: SingleRequestArgs = {
     authHeaders,
-    res,
     path: `/playlists/${playlistID}/`,
     config: {
       params: {
         fields: initialFields,
       },
     },
-  });
+  };
+  if (res) args.res = res;
+  return await singleRequest<GetPlaylistData>(args);
 };
 
 interface GetPlaylistDetailsNextPageArgs extends EndpointHandlerWithResArgs {
@@ -254,7 +257,9 @@ const removePlaylistItems: (
 // non-endpoints, i.e. convenience wrappers
 // ---------
 
-interface CheckPlaylistEditableArgs extends EndpointHandlerWithResArgs {
+interface CheckPlaylistEditableArgs
+  extends Omit<EndpointHandlerWithResArgs, "res"> {
+  res?: Res;
   playlistID: string;
   userID: string;
 }
@@ -272,12 +277,13 @@ const checkPlaylistEditable: (
   userID,
 }) => {
   let checkFields = ["collaborative", "owner(id)"];
-  const { resp, error, message } = await getPlaylistDetailsFirstPage({
-    res,
+  let args: GetPlaylistDetailsFirstPageArgs = {
     authHeaders,
     initialFields: checkFields.join(),
     playlistID,
-  });
+  };
+  if (res) args.res = res;
+  const { resp, error, message } = await getPlaylistDetailsFirstPage(args);
   if (!resp) return { status: false, error, message };
 
   // https://web.archive.org/web/20241226081630/https://developer.spotify.com/documentation/web-api/concepts/playlists#:~:text=A%20playlist%20can%20also%20be%20made%20collaborative
diff --git a/controllers/operations.ts b/controllers/operations.ts
index 5b7a30e..22e4531 100644
--- a/controllers/operations.ts
+++ b/controllers/operations.ts
@@ -687,6 +687,19 @@ const populateChain: RequestHandler = async (req, res) => {
     // (although that's a challenge of its own)
     const newGraph = new myGraph(playlistIDs, allLinks);
     const affectedPlaylists = newGraph.getAllHeads(rootPl.id);
+
+    const editableStatuses = await Promise.all(
+      affectedPlaylists.map((pl) => {
+        return checkPlaylistEditable({
+          authHeaders,
+          playlistID: pl,
+          userID: uID,
+        });
+      })
+    );
+    if (editableStatuses.some((statusObj) => statusObj.status === false))
+      return null;
+
     const affectedPlaylistsTracks = await Promise.all(
       affectedPlaylists.map((pl) => {
         return _getPlaylistTracks({ res, authHeaders, playlistID: pl });