diff --git a/src/routes/postWarning.ts b/src/routes/postWarning.ts
index dfc7819..6feedef 100644
--- a/src/routes/postWarning.ts
+++ b/src/routes/postWarning.ts
@@ -22,8 +22,15 @@ export function postWarning(req: Request, res: Response) {
     let resultStatus = "";
 
     if (enabled) {
-        db.prepare('run', 'INSERT INTO warnings (userID, issueTime, issuerUserID, enabled) VALUES (?, ?, ?, 1)', [userID, issueTime, issuerUserID]);
-        resultStatus = "issued to";
+        let previousWarning = db.prepare('get', 'SELECT * FROM warnings WHERE userID = ? AND issuerUserID = ?', [userID, issuerUserID]);
+
+        if (!previousWarning) {
+            db.prepare('run', 'INSERT INTO warnings (userID, issueTime, issuerUserID, enabled) VALUES (?, ?, ?, 1)', [userID, issueTime, issuerUserID]);
+            resultStatus = "issued to";
+        } else {
+            res.status(409).send();
+            return;
+        }
     } else {
         db.prepare('run', 'UPDATE warnings SET enabled = 0 WHERE userID = ? AND issuerUserID = ?', [userID, issuerUserID]);
         resultStatus = "removed from";
diff --git a/test/cases/postWarning.ts b/test/cases/postWarning.ts
index 7122334..6a8c13d 100644
--- a/test/cases/postWarning.ts
+++ b/test/cases/postWarning.ts
@@ -32,6 +32,30 @@ describe('postWarning', () => {
             });
     });
 
+    it('Should be not be able to create a duplicate warning if vip', (done: Done) => {
+        let json = {
+            issuerUserID: 'warning-vip',
+            userID: 'warning-0',
+        };
+
+        request.post(getbaseURL()
+            + "/api/warnUser", {json},
+            (err, res, body) => {
+                if (err) done(err);
+                else if (res.statusCode === 409) {
+                    let row = db.prepare('get', "SELECT userID, issueTime, issuerUserID, enabled FROM warnings WHERE userID = ?", [json.userID]);
+                    if (row?.enabled == 1 && row?.issuerUserID == getHash(json.issuerUserID)) {
+                        done();
+                    } else {
+                        done("Warning missing from database");
+                    }
+                } else {
+                    console.log(body);
+                    done("Status code was " + res.statusCode);
+                }
+            });
+    });
+
     it('Should be able to remove warning if vip', (done: Done) => {
         let json = {
             issuerUserID: 'warning-vip',