diff --git a/resources/js/components/code-block.tsx b/resources/js/components/code-block.tsx
index cf04563d3..96e2b0486 100644
--- a/resources/js/components/code-block.tsx
+++ b/resources/js/components/code-block.tsx
@@ -7,10 +7,12 @@ import { cn } from '@/lib/utils';
 
 export function CodeBlock({
     html,
+    fullHtml,
     language,
     isCopyable = true,
 }: {
     html: string;
+    fullHtml?: string;
     language: string | null;
     isCopyable?: boolean;
 }) {
@@ -34,7 +36,16 @@ export function CodeBlock({
             return;
         }
 
-        if (await copy(codeRef.current.textContent ?? '')) {
+        let code = codeRef.current.textContent ?? '';
+
+        if (fullHtml !== undefined) {
+            // The server escapes the code while highlighting it, and a template runs nothing.
+            const template = document.createElement('template');
+            template.innerHTML = fullHtml;
+            code = template.content.textContent ?? '';
+        }
+
+        if (await copy(code)) {
             setIsCopied(true);
 
             return;
diff --git a/resources/js/components/commit-body.tsx b/resources/js/components/commit-body.tsx
index fac23d0a0..6ecabe883 100644
--- a/resources/js/components/commit-body.tsx
+++ b/resources/js/components/commit-body.tsx
@@ -91,6 +91,7 @@ export function BodySegments({
                             <CodeBlock
                                 key={index}
                                 html={segment.html}
+                                fullHtml={segment.fullHtml}
                                 language={segment.language}
                                 isCopyable={!isStatic}
                             />
@@ -147,7 +148,11 @@ export function FoldedCommitBody({
     return (
         <div ref={bodyRef} tabIndex={-1} className="outline-none">
             <CommitBody
-                segments={isUnfolded ? segments : previewSegments}
+                segments={
+                    isUnfolded
+                        ? segments
+                        : withFullBlocks(previewSegments, segments)
+                }
                 mentions={mentions}
                 className={className}
             />
@@ -165,6 +170,24 @@ export function FoldedCommitBody({
     );
 }
 
+/**
+ * The preview is the start of the body, so its code blocks are the body's first ones, in order. The last may be cut
+ * to its first lines; each gets the whole block to copy.
+ */
+function withFullBlocks(
+    previewSegments: BodySegment[],
+    segments: BodySegment[],
+): BodySegment[] {
+    const blocks = segments.filter((segment) => segment.type === 'block');
+    let index = 0;
+
+    return previewSegments.map((segment) =>
+        segment.type === 'block'
+            ? { ...segment, fullHtml: blocks[index++]?.html }
+            : segment,
+    );
+}
+
 export function CommitBodyExcerpt({
     segments,
     previewSegments = null,
diff --git a/resources/js/types/commit.ts b/resources/js/types/commit.ts
index 12790e4d3..4e6b99583 100644
--- a/resources/js/types/commit.ts
+++ b/resources/js/types/commit.ts
@@ -50,7 +50,13 @@ export type CommitImage = {
 export type BodySegment =
     | { type: 'text'; text: string }
     | { type: 'code'; code: string }
-    | { type: 'block'; language: string | null; html: string };
+    | {
+          type: 'block';
+          language: string | null;
+          html: string;
+          // The whole block, when a preview shows only its first lines, so copying it still copies all of it.
+          fullHtml?: string;
+      };
 
 export type CommitTranslation = {
     language: string;