diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3877cab5c..669dc5b87 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,6 @@
 # Changelog
 
-All notable changes to this project will be documented in this file. 
+All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
@@ -25,6 +25,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Sidebar panel overflow for plugins (#1266, #1269)
 - Extra border around code output in the instructions panel (#1253)
 - Line numbering alignment in code blocks in the instructions panel (#1259)
+- Extra lines added at the start of some code blocks (#1267)
 
 ## [0.33.0] - 2025-10-15
 
diff --git a/src/components/Menus/Sidebar/InstructionsPanel/InstructionsPanel.jsx b/src/components/Menus/Sidebar/InstructionsPanel/InstructionsPanel.jsx
index 9db70ab7e..32c2d74a1 100644
--- a/src/components/Menus/Sidebar/InstructionsPanel/InstructionsPanel.jsx
+++ b/src/components/Menus/Sidebar/InstructionsPanel/InstructionsPanel.jsx
@@ -17,16 +17,25 @@ import RemoveInstructionsModal from "../../../Modals/RemoveInstructionsModal";
 import Prism from "prismjs";
 import populateMarkdownTemplate from "../../../../utils/populateMarkdownTemplate";
 
+let prismConfigured = false;
+
 const InstructionsPanel = () => {
   useEffect(() => {
     // prism and prism plugin config
     Prism.manual = true;
-    if (Prism.plugins.NormalizeWhitespace) {
+    if (Prism.plugins.NormalizeWhitespace && !prismConfigured) {
       Prism.plugins.NormalizeWhitespace.setDefaults({
         "remove-indent": false,
         "remove-initial-line-feed": true,
         "left-trim": false,
       });
+      Prism.hooks.add("before-sanity-check", function (env) {
+        if (!env.code) return;
+
+        // Remove multiple leading blank lines (empty or whitespace-only)
+        env.code = env.code.replace(/^(?:\s*\n)+/, "");
+      });
+      prismConfigured = true;
     }
   }, []);
   const [showModal, setShowModal] = useState(false);