diff --git a/docs/changelog.md b/docs/changelog.md
index 4c3b19bf..385ca4d7 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -1,5 +1,9 @@
 # Change Log
 
+## 2.3.1
+
+- Added minimum version pin for nbformat
+
 ## 2.3.0
 
 - Notebooks that are loaded with papermill now upgrade the document to the latest spec version (to support cell-id assignments).
diff --git a/requirements.txt b/requirements.txt
index 3d065681..a5cd29fd 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,7 @@
 ansiwrap
 click
 pyyaml
-nbformat
+nbformat >= 5.1.2
 nbclient >= 0.2.0
 tqdm >= 4.32.2
 requests