diff --git a/libraries/logger/CHANGELOG.md b/libraries/logger/CHANGELOG.md
index c130189ccc..a581cf4077 100644
--- a/libraries/logger/CHANGELOG.md
+++ b/libraries/logger/CHANGELOG.md
@@ -1,3 +1,7 @@
+## v3.1.1
+
+* Handle malformed requests in the req serializer
+
 ## v3.0.0
 
 * Improve logging in Google Cloud Platform. Set environment variable `GCP_LOGGING=true` to enable.
diff --git a/libraries/logger/package.json b/libraries/logger/package.json
index 7d6d0337db..78e9a74595 100644
--- a/libraries/logger/package.json
+++ b/libraries/logger/package.json
@@ -7,7 +7,7 @@
     "url": "https://github.com/overleaf/overleaf"
   },
   "license": "AGPL-3.0-only",
-  "version": "3.1.0",
+  "version": "3.1.1",
   "scripts": {
     "test": "mocha --grep=$MOCHA_GREP test/**/*.js",
     "format": "prettier --list-different $PWD/'**/*.js'",
diff --git a/libraries/logger/serializers.js b/libraries/logger/serializers.js
index 28581d863f..37b84e60e3 100644
--- a/libraries/logger/serializers.js
+++ b/libraries/logger/serializers.js
@@ -29,18 +29,20 @@ function reqSerializer(req) {
       'content-length': headers['content-length'],
     },
   }
-  const projectId =
-    req.params.projectId || req.params.project_id || req.params.Project_id
-  const userId = req.params.userId || req.params.user_id
-  const docId = req.params.docId || req.params.doc_id
-  if (projectId) {
-    entry.projectId = projectId
-  }
-  if (userId) {
-    entry.userId = userId
-  }
-  if (docId) {
-    entry.docId = docId
+  if (req.params) {
+    const projectId =
+      req.params.projectId || req.params.project_id || req.params.Project_id
+    const userId = req.params.userId || req.params.user_id
+    const docId = req.params.docId || req.params.doc_id
+    if (projectId) {
+      entry.projectId = projectId
+    }
+    if (userId) {
+      entry.userId = userId
+    }
+    if (docId) {
+      entry.docId = docId
+    }
   }
   return entry
 }