diff --git a/packages/hydrooj/package.json b/packages/hydrooj/package.json
index de4462891..13b94aa26 100644
--- a/packages/hydrooj/package.json
+++ b/packages/hydrooj/package.json
@@ -1,6 +1,6 @@
 {
     "name": "hydrooj",
-    "version": "2.26.15",
+    "version": "2.26.16",
     "bin": "bin/hydrooj.js",
     "main": "dist/loader.js",
     "typings": "dist/loader.d.ts",
diff --git a/packages/hydrooj/src/handler/training.ts b/packages/hydrooj/src/handler/training.ts
index 3f2077770..9b34d21c5 100644
--- a/packages/hydrooj/src/handler/training.ts
+++ b/packages/hydrooj/src/handler/training.ts
@@ -123,7 +123,7 @@ class TrainingDetailHandler extends Handler {
         for (const node of tdoc.dag) {
             ndict[node._id] = node;
             const totalCount = node.pids.length;
-            const doneCount = Set.union(new Set(node.pids), donePids).size;
+            const doneCount = Set.intersection(new Set(node.pids), donePids).size;
             const nsdoc = {
                 progress: totalCount ? Math.floor(100 * (doneCount / totalCount)) : 100,
                 isDone: training.isDone(node, doneNids, donePids),