diff --git a/web/api.py b/web/api.py
index 03bd387..ba5fcbf 100644
--- a/web/api.py
+++ b/web/api.py
@@ -7,6 +7,7 @@ import glob as _glob
 import logging
 import mimetypes
 import shutil
+import sqlite3
 import subprocess
 import sys
 import time
@@ -445,9 +446,13 @@ def create_project_link(body: ProjectLinkCreate):
     if not models.get_project(conn, body.to_project):
         conn.close()
         raise HTTPException(404, f"Project '{body.to_project}' not found")
-    link = models.create_project_link(
-        conn, body.from_project, body.to_project, body.type, body.description
-    )
+    try:
+        link = models.create_project_link(
+            conn, body.from_project, body.to_project, body.type, body.description
+        )
+    except sqlite3.IntegrityError:
+        conn.close()
+        raise HTTPException(409, "Link already exists")
     conn.close()
     return link