diff --git a/src/tools/hashline-edit/constants.ts b/src/tools/hashline-edit/constants.ts
index 4ecf66c4..2eac4d9c 100644
--- a/src/tools/hashline-edit/constants.ts
+++ b/src/tools/hashline-edit/constants.ts
@@ -7,5 +7,4 @@ export const HASHLINE_DICT = Array.from({ length: 256 }, (_, i) => {
 })
 
 export const HASHLINE_REF_PATTERN = /^([0-9]+)#([ZPMQVRWSNKTXJBYH]{2})$/
-export const HASHLINE_OUTPUT_PATTERN = /^([0-9]+)#([ZPMQVRWSNKTXJBYH]{2}):(.*)$/
-export const HASHLINE_LEGACY_REF_PATTERN = /^([0-9]+):([0-9a-fA-F]{2,})$/
+export const HASHLINE_OUTPUT_PATTERN = /^([0-9]+)#([ZPMQVRWSNKTXJBYH]{2})\|(.*)$/
diff --git a/src/tools/hashline-edit/validation.test.ts b/src/tools/hashline-edit/validation.test.ts
index fc401cbf..cf2457ab 100644
--- a/src/tools/hashline-edit/validation.test.ts
+++ b/src/tools/hashline-edit/validation.test.ts
@@ -61,46 +61,3 @@ describe("validateLineRef", () => {
       .toThrow(/>>>\s+2#[ZPMQVRWSNKTXJBYH]{2}\|two/)
   })
 })
-
-describe("legacy LINE:HEX backward compatibility", () => {
-  it("parses legacy LINE:HEX ref", () => {
-    //#given
-    const ref = "42:ab"
-
-    //#when
-    const result = parseLineRef(ref)
-
-    //#then
-    expect(result).toEqual({ line: 42, hash: "ab" })
-  })
-
-  it("parses legacy LINE:HEX ref with uppercase hex", () => {
-    //#given
-    const ref = "10:FF"
-
-    //#when
-    const result = parseLineRef(ref)
-
-    //#then
-    expect(result).toEqual({ line: 10, hash: "FF" })
-  })
-
-  it("legacy ref fails validation with hash mismatch, not parse error", () => {
-    //#given
-    const lines = ["function hello() {"]
-
-    //#when / #then
-    expect(() => validateLineRef(lines, "1:ab")).toThrow(/>>>\s+1#[ZPMQVRWSNKTXJBYH]{2}\|/)
-  })
-
-  it("extracts legacy ref from content with markers", () => {
-    //#given
-    const ref = ">>> 42:ab|const x = 1"
-
-    //#when
-    const result = parseLineRef(ref)
-
-    //#then
-    expect(result).toEqual({ line: 42, hash: "ab" })
-  })
-})
diff --git a/src/tools/hashline-edit/validation.ts b/src/tools/hashline-edit/validation.ts
index f81ccbaa..72a33286 100644
--- a/src/tools/hashline-edit/validation.ts
+++ b/src/tools/hashline-edit/validation.ts
@@ -1,5 +1,5 @@
 import { computeLineHash } from "./hash-computation"
-import { HASHLINE_REF_PATTERN, HASHLINE_LEGACY_REF_PATTERN } from "./constants"
+import { HASHLINE_REF_PATTERN } from "./constants"
 
 export interface LineRef {
   line: number
@@ -13,16 +13,13 @@ interface HashMismatch {
 
 const MISMATCH_CONTEXT = 2
 
-const LINE_REF_EXTRACT_PATTERN = /([0-9]+#[ZPMQVRWSNKTXJBYH]{2}|[0-9]+:[0-9a-fA-F]{2,})/
+const LINE_REF_EXTRACT_PATTERN = /([0-9]+#[ZPMQVRWSNKTXJBYH]{2})/
 
 function normalizeLineRef(ref: string): string {
   const trimmed = ref.trim()
   if (HASHLINE_REF_PATTERN.test(trimmed)) {
     return trimmed
   }
-  if (HASHLINE_LEGACY_REF_PATTERN.test(trimmed)) {
-    return trimmed
-  }
 
   const extracted = trimmed.match(LINE_REF_EXTRACT_PATTERN)
   if (extracted) {
@@ -41,13 +38,6 @@ export function parseLineRef(ref: string): LineRef {
       hash: match[2],
     }
   }
-  const legacyMatch = normalized.match(HASHLINE_LEGACY_REF_PATTERN)
-  if (legacyMatch) {
-    return {
-      line: Number.parseInt(legacyMatch[1], 10),
-      hash: legacyMatch[2],
-    }
-  }
   throw new Error(
     `Invalid line reference format: "${ref}". Expected format: "LINE#ID" (e.g., "42#VK")`
   )