diff --git a/.changeset/light-experts-refuse.md b/.changeset/light-experts-refuse.md
new file mode 100644
index 000000000..9ec19d55b
--- /dev/null
+++ b/.changeset/light-experts-refuse.md
@@ -0,0 +1,5 @@
+---
+"@guardian/cdk": minor
+---
+
+GuLambdaFunction uses JSON logging by default, for compatibility with ApplicationLogLevel