Update MathJax URL.
diff --git a/pom.xml b/pom.xml
index a9ae526..4292a12 100644
--- a/pom.xml
+++ b/pom.xml
@@ -58,7 +58,7 @@
     <rng.pmd.dep.version>6.14.0</rng.pmd.dep.version>
     <rng.checkstyle.version>3.0.0</rng.checkstyle.version>
     <rng.checkstyle.dep.version>8.20</rng.checkstyle.dep.version>
-    <rng.mathjax.version>2.7.2</rng.mathjax.version>
+    <rng.mathjax.url>https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js</rng.mathjax.url>
     <rng.antrun.version>1.8</rng.antrun.version>
     <!-- Workaround to avoid duplicating config files. -->
     <rng.parent.dir>${basedir}</rng.parent.dir>
@@ -253,7 +253,7 @@
         <artifactId>maven-javadoc-plugin</artifactId>
         <configuration>
           <!-- Enable MathJax -->
-          <additionalOptions>${doclint.javadoc.qualifier} ${allowscript.javadoc.qualifier} -header '&lt;script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/${rng.mathjax.version}/MathJax.js?config=TeX-AMS-MML_HTMLorMML"&gt;&lt;/script&gt;'</additionalOptions>
+          <additionalOptions>${doclint.javadoc.qualifier} ${allowscript.javadoc.qualifier} -header '&lt;script type="text/javascript" async src="${rng.mathjax.url}"&gt;&lt;/script&gt;'</additionalOptions>
         </configuration>
       </plugin>
       <plugin>
@@ -354,7 +354,7 @@
         <artifactId>maven-javadoc-plugin</artifactId>
         <configuration>
           <!-- Enable MathJax -->
-          <additionalOptions>${doclint.javadoc.qualifier} ${allowscript.javadoc.qualifier} -header '&lt;script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/${rng.mathjax.version}/MathJax.js?config=TeX-AMS-MML_HTMLorMML"&gt;&lt;/script&gt;'</additionalOptions>
+          <additionalOptions>${doclint.javadoc.qualifier} ${allowscript.javadoc.qualifier} -header '&lt;script type="text/javascript" async src="${rng.mathjax.url}"&gt;&lt;/script&gt;'</additionalOptions>
         </configuration>
       </plugin>
       <plugin>
diff --git a/src/site/site.xml b/src/site/site.xml
index dbc031a..b69aba8 100644
--- a/src/site/site.xml
+++ b/src/site/site.xml
@@ -28,7 +28,7 @@
 
   <body>
     <head>
-      <![CDATA[<script type="text/javascript" src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML">
+      <![CDATA[<script type="text/javascript" id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js">
       </script>]]>
     </head>