diff --git a/.changeset/mermaid-block-diagrams.md b/.changeset/mermaid-block-diagrams.md
new file mode 100644
index 000000000..4a086982a
--- /dev/null
+++ b/.changeset/mermaid-block-diagrams.md
@@ -0,0 +1,5 @@
+---
+"gitbook": patch
+---
+
+Fix Mermaid block diagrams falling back to a code block on published sites.