diff --git a/.changeset/strong-dryers-pay.md b/.changeset/strong-dryers-pay.md
new file mode 100644
index 000000000..495cde202
--- /dev/null
+++ b/.changeset/strong-dryers-pay.md
@@ -0,0 +1,5 @@
+---
+'mermaid': patch
+---
+
+fix: correctly render non-directional lines for '---' in block diagrams