diff --git a/.vscode/settings.json b/.vscode/settings.json
index b09b4e0..47bf9b0 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -3,5 +3,8 @@
   "editor.formatOnSave": true,
   "prettier.printWidth": 160,
   "prettier.tabWidth": 2,
-  "cSpell.words": ["fallstack"]
+  "cSpell.words": ["fallstack"],
+  "[dotenv]": {
+    "editor.defaultFormatter": "foxundermoon.shell-format"
+  }
 }
diff --git a/src/lib/completeAction.ts b/src/lib/completeAction.ts
index ddab744..78bf032 100644
--- a/src/lib/completeAction.ts
+++ b/src/lib/completeAction.ts
@@ -9,6 +9,15 @@ export async function completeAction(studentCode: string, actionName: string) {
 
   if (!action) return null;
 
+  const alreadyCompleted = await prisma.actionCompletion.findFirst({
+    where: {
+      studentCode,
+      actionId: action.id,
+    },
+  });
+
+  if (alreadyCompleted) return null;
+
   const studentAction = await prisma.actionCompletion.create({
     data: {
       studentCode,