diff --git a/custom.js b/custom.js
new file mode 100644
index 0000000..d24560d
--- /dev/null
+++ b/custom.js
@@ -0,0 +1,6 @@
+window.MathJax = {
+  tex: {
+    tags: 'ams'
+  }
+};
+
diff --git a/index.qmd b/index.qmd
index 2402f7d..4b56d84 100644
--- a/index.qmd
+++ b/index.qmd
@@ -24,14 +24,7 @@ format:
         pagetitle: "De-Fence"
         html-math-method: mathjax
         include-in-header:
-          - text: |
-              <script>
-              window.MathJax = {
-                tex: {
-                  tags: 'ams'
-                }
-              };
-              </script>   
+          - file: custom.html
 execute:
   daemon: false
 highlight-style: github