diff --git a/docs/index.html b/docs/index.html
index 015ce128b..7c92a1e31 100644
--- a/docs/index.html
+++ b/docs/index.html
@@ -57,6 +57,7 @@
       let parser = new DOMParser();
       let currentCodeExample = 0;
       let colorize = [];
+      let num = 0;
 
       function colorizeEverything(html) {
         initEditor(monaco);
diff --git a/packages/mermaid/src/docs/index.html b/packages/mermaid/src/docs/index.html
index 2d6e1c714..29643d974 100644
--- a/packages/mermaid/src/docs/index.html
+++ b/packages/mermaid/src/docs/index.html
@@ -57,6 +57,7 @@
       let parser = new DOMParser();
       let currentCodeExample = 0;
       let colorize = [];
+      let num = 0;
 
       function colorizeEverything(html) {
         initEditor(monaco);