diff --git a/src/cli/lint/internalLints/upgrade/patches/8.2.1/collapseDuplicateMergeKeys.test.ts b/src/cli/lint/internalLints/upgrade/patches/8.2.1/collapseDuplicateMergeKeys.test.ts
index c41692b5b..12f2e3c9f 100644
--- a/src/cli/lint/internalLints/upgrade/patches/8.2.1/collapseDuplicateMergeKeys.test.ts
+++ b/src/cli/lint/internalLints/upgrade/patches/8.2.1/collapseDuplicateMergeKeys.test.ts
@@ -208,6 +208,72 @@ steps:
       });
     });
 
+    it('should handle comments', async () => {
+      const input = `
+steps:
+- <<: *prod # hi
+  <<: *timeout
+  label: 'My Step'
+  command: echo 'Hello, world!'
+
+- <<: *prod
+  <<: *timeout# hi
+  label: 'My Step'
+  command: echo 'Hello, world!'
+
+- <<: *prod # hello
+  <<: *timeout# world
+  label: 'My Step'
+  command: echo 'Hello, world!'
+
+- label: something
+  <<: *prod # hello
+  <<: *timeout# world
+  command: echo 'Hello, world!'
+`;
+
+      vol.fromJSON({
+        '.buildkite/pipeline.yml': input,
+      });
+
+      await expect(
+        tryCollapseDuplicateMergeKeys({
+          ...baseArgs,
+          mode,
+        }),
+      ).resolves.toEqual({ result: 'apply' });
+
+      expect(volToJson()).toEqual({
+        '.buildkite/pipeline.yml':
+          mode === 'lint'
+            ? input
+            : `
+steps:
+  # hi
+- <<: [*prod, *timeout]
+  label: 'My Step'
+  command: echo 'Hello, world!'
+
+  # hi
+- <<: [*prod, *timeout]
+  label: 'My Step'
+  command: echo 'Hello, world!'
+
+  # hello
+  # world
+- <<: [*prod, *timeout]
+  label: 'My Step'
+  command: echo 'Hello, world!'
+
+- label: something
+  # hello
+  # world
+  <<: [*prod, *timeout]
+  command: echo 'Hello, world!'
+`,
+      });
+    });
+
     it('should not bother if the keys are separated by other keys', async () => {
       const input = `steps:
   - <<: *prod
diff --git a/src/cli/lint/internalLints/upgrade/patches/8.2.1/collapseDuplicateMergeKeys.ts b/src/cli/lint/internalLints/upgrade/patches/8.2.1/collapseDuplicateMergeKeys.ts
index 7cdaec5e8..dbbde40fe 100644
--- a/src/cli/lint/internalLints/upgrade/patches/8.2.1/collapseDuplicateMergeKeys.ts
+++ b/src/cli/lint/internalLints/upgrade/patches/8.2.1/collapseDuplicateMergeKeys.ts
@@ -45,10 +45,18 @@ const collapseDuplicateMergeKeys: PatchFunction = async ({
 const collapseDuplicateMergeKeysInFile = (input: string) =>
   replaceAllUntilStable(
     input,
-    /^([ \-]*)<<: \[?(\*[^\n\]]+)\]?$\n^( *)<<: \[?(\*[^\n\]]+)\]?$/gm,
-    (match, a, b, c, d) => {
-      if (a.length === c.length) {
-        return `${a}<<: [${b}, ${d}]`;
+    /^([ \-]*)<<: \[?(\*[^\n#\]]+)\]?(\s*#.*)?$\n^( *)<<: \[?(\*[^\n#\]]+)\]?(\s*#.*)?$/gm,
+    (match, prefixA, keyA, commentA, prefixB, keyB, commentB) => {
+      if (prefixA.length === prefixB.length) {
+        return [
+          ...(commentA
+            ? [`${' '.repeat(prefixA.length)}${commentA.trim()}`]
+            : []),
+          ...(commentB
+            ? [`${' '.repeat(prefixA.length)}${commentB.trim()}`]
+            : []),
+          `${prefixA}<<: [${keyA.trim()}, ${keyB.trim()}]`,
+        ].join('\n');
       }
       return match;
     },