diff --git a/.github/actions/docs/entrypoint.sh b/.github/actions/docs/entrypoint.sh
index 203f98e62..7ac74e427 100755
--- a/.github/actions/docs/entrypoint.sh
+++ b/.github/actions/docs/entrypoint.sh
@@ -1,7 +1,13 @@
 #!/bin/sh -l
 
+set -e
+
 apt-get update
 apt-get install -y git wget
+
+# Fix github "detected dubious ownership" error
+git config --global --add safe.directory /github/workspace
+
 git reset --hard HEAD
 
 # Create the directories
diff --git a/CHANGELOG.md b/CHANGELOG.md
index e5e516a65..f484d6fc1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # Changelog
 
+## [2.13.2](https://github.com/googleapis/google-api-php-client/compare/v2.13.1...v2.13.2) (2023-03-23)
+
+
+### Bug Fixes
+
+* Calling class_exists with null in Google\Model ([#2405](https://github.com/googleapis/google-api-php-client/issues/2405)) ([5ed4edc](https://github.com/googleapis/google-api-php-client/commit/5ed4edc9315110a715e9763d27ee6761e1aaa00a))
+
 ## [2.13.1](https://github.com/googleapis/google-api-php-client/compare/v2.13.0...v2.13.1) (2023-03-13)
 
 
diff --git a/src/Model.php b/src/Model.php
index 95328f5d3..87f437d66 100644
--- a/src/Model.php
+++ b/src/Model.php
@@ -294,7 +294,7 @@ protected function keyType($key)
         $keyType = $key . "Type";
 
         // ensure keyType is a valid class
-        if (property_exists($this, $keyType) && class_exists($this->$keyType)) {
+        if (property_exists($this, $keyType) && $this->$keyType !== null && class_exists($this->$keyType)) {
             return $this->$keyType;
         }
     }