diff --git a/renovate.json b/renovate.json
index 25e7e3d5..0a8f52d6 100644
--- a/renovate.json
+++ b/renovate.json
@@ -43,6 +43,12 @@
       "matchPackageNames": ["pydantic-ai-slim"],
       "allowedVersions": "<1.59.0"
     },
+    {
+      "groupName": "allowed langfuse versions",
+      "matchManagers": ["pep621"],
+      "matchPackageNames": ["langfuse"],
+      "allowedVersions": "<3.12.0"
+    },
     {
       "enabled": false,
       "groupName": "ignored js dependencies",
diff --git a/src/backend/pyproject.toml b/src/backend/pyproject.toml
index c6bb8f7e..734350b3 100644
--- a/src/backend/pyproject.toml
+++ b/src/backend/pyproject.toml
@@ -48,7 +48,7 @@ dependencies = [
     "factory_boy==3.3.3",
     "gunicorn==25.1.0",
     "jsonschema==4.26.0",
-    "langfuse==3.14.5",
+    "langfuse==3.11.2",
     "lxml==6.0.2",
     "markdown==3.10.2",
     "mozilla-django-oidc==5.0.2",