diff --git a/mkdocs.yml b/mkdocs.yml
index 2cac189..28ef036 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -21,11 +21,11 @@ markdown_extensions:
   - pymdownx.details
   - pymdownx.highlight
   - pymdownx.superfences
-    # make exceptions to highlighting of code:
-    custom_fences:
-      - name: mermaid
-        class: mermaid
-        format: !!python/name:mermaid2.fence_mermaid
+      # make exceptions to highlighting of code:
+      custom_fences:
+        - name: mermaid
+          class: mermaid
+          format: !!python/name:mermaid2.fence_mermaid
   - pymdownx.inlinehilite
   - pymdownx.keys
   - pymdownx.tabbed