diff --git a/scripts/js/lib/api/htmlToMd.test.ts b/scripts/js/lib/api/htmlToMd.test.ts
index 68c6cf395e9..96147784198 100644
--- a/scripts/js/lib/api/htmlToMd.test.ts
+++ b/scripts/js/lib/api/htmlToMd.test.ts
@@ -100,10 +100,10 @@ Can be either (1) a dictionary mapping XX angle values to fidelity at that angle
 // Transform code blocks
 // ------------------------------------------------------------------
 
-test("translate codeblocks to code fences with lang python", async () => {
+test("translate codeblocks to code fences with default lang python", async () => {
   expect(
     await toMd(`
-    <div class='highlight-python notranslate'>
+    <div class='highlight-default notranslate'>
     <div role='main'>
 <pre><span></span><span class='n'>QiskitRuntimeService</span><span class='o'>.</span><span class='n'>backends</span><span class='p'>(</span>
     <span class='n'>filters</span><span class='o'>=</span><span class='k'>lambda</span> <span class='n'>b</span><span class='p'>:</span> <span class='n'>b</span><span class='o'>.</span><span class='n'>max_shots</span> <span class='o'>&gt;</span> <span class='mi'>50000</span><span class='p'>)</span>
@@ -122,6 +122,28 @@ QiskitRuntimeService.backends(
 `);
 });
 
+test("translate codeblocks to code fences with lang c", async () => {
+  expect(
+    await toMd(`
+    <div class='highlight-c notranslate'>
+    <div role='main'>
+<pre><span></span><span class='n'>QiskitRuntimeService</span><span class='o'>.</span><span class='n'>backends</span><span class='p'>(</span>
+    <span class='n'>filters</span><span class='o'>=</span><span class='k'>lambda</span> <span class='n'>b</span><span class='p'>:</span> <span class='n'>b</span><span class='o'>.</span><span class='n'>max_shots</span> <span class='o'>&gt;</span> <span class='mi'>50000</span><span class='p'>)</span>
+<span class='n'>QiskitRuntimeService</span><span class='o'>.</span><span class='n'>backends</span><span class='p'>(</span>
+    <span class='n'>filters</span><span class='o'>=</span><span class='k'>lambda</span> <span class='n'>x</span><span class='p'>:</span> <span class='p'>(</span><span class='s2'>&quot;rz&quot;</span> <span class='ow'>in</span> <span class='n'>x</span><span class='o'>.</span><span class='n'>basis_gates</span> <span class='p'>)</span>
+</pre>
+    </div>
+    </div>
+    `),
+  ).toEqual(`\`\`\`c
+QiskitRuntimeService.backends(
+    filters=lambda b: b.max_shots > 50000)
+QiskitRuntimeService.backends(
+    filters=lambda x: ("rz" in x.basis_gates )
+\`\`\`
+`);
+});
+
 // ------------------------------------------------------------------
 // Transform methods and attributes
 // ------------------------------------------------------------------