diff --git a/packages/hashline/src/grammar.lark b/packages/hashline/src/grammar.lark
index 8a056d4e1..d2e016ecb 100644
--- a/packages/hashline/src/grammar.lark
+++ b/packages/hashline/src/grammar.lark
@@ -5,7 +5,7 @@ end_patch:   "*** End Patch" LF?
 file_patch: file_header hunk+
 file_header: "¶" filename "#" file_hash LF
 file_hash: /[0-9A-F]{4}/
-filename: /[^\s#]+/
+filename: /[^#\r\n]+/
 
 hunk: replace_hunk | replace_block_hunk | insert_hunk | delete_hunk | delete_block_hunk
 replace_hunk: replace_anchor LF emit_op*
diff --git a/packages/hashline/src/input.ts b/packages/hashline/src/input.ts
index 9864d95b6..5b5774b5e 100644
--- a/packages/hashline/src/input.ts
+++ b/packages/hashline/src/input.ts
@@ -50,14 +50,14 @@ function stripApplyPatchPathNoise(pathText: string): string {
  * Best-effort recovery for `¶`-prefixed lines the strict tokenizer
  * rejects. Strips apply_patch keyword noise (`Update File:`, `Update:`,
  * etc.) and an extra leading `***` (some models emit a hybrid `¶***foo.ts`
- * shape), then expects `PATH(#HASH)?` with no embedded whitespace.
+ * shape), then expects `PATH(#HASH)?`.
  * Returns `null` when no clean path can be salvaged.
  */
 function tryParseRecoveryHeader(line: string, cwd?: string): RawSection | null {
 	if (!line.startsWith(HL_FILE_PREFIX)) return null;
 	const body = stripApplyPatchPathNoise(line.slice(HL_FILE_PREFIX.length).trim());
 	if (body.length === 0) return null;
-	const match = new RegExp(`^(\\S+?)(?:#([0-9A-Fa-f]{${HL_FILE_HASH_LENGTH}}))?\\s*$`).exec(body);
+	const match = new RegExp(`^(.+?)(?:#([0-9A-Fa-f]{${HL_FILE_HASH_LENGTH}}))?\\s*$`).exec(body);
 	if (match === null) return null;
 	const path = normalizeHashlinePath(match[1], cwd);
 	if (path.length === 0) return null;
diff --git a/packages/hashline/src/tokenizer.ts b/packages/hashline/src/tokenizer.ts
index 19ffe7164..4bbfbe80c 100644
--- a/packages/hashline/src/tokenizer.ts
+++ b/packages/hashline/src/tokenizer.ts
@@ -312,28 +312,22 @@ function tryParseHunkHeader(line: string): ParsedHunkHeader | null {
 function tryParseHeader(line: string): { path: string; fileHash?: string } | null {
 	if (!line.startsWith(HL_FILE_PREFIX)) return null;
 	const end = trimEndIndex(line);
-	let index = FILE_PREFIX_LENGTH;
-	if (index >= end) return null;
-	const pathStart = index;
-	while (index < end) {
-		const code = line.charCodeAt(index);
-		if (code === CHAR_HASH || code === CHAR_SPACE || code === CHAR_TAB) break;
-		index++;
-	}
-	if (index === pathStart) return null;
-	const path = line.slice(pathStart, index);
+	if (FILE_PREFIX_LENGTH >= end) return null;
+
+	let pathEnd = end;
 	let fileHash: string | undefined;
-	if (index < end && line.charCodeAt(index) === CHAR_HASH) {
-		const hashStart = index + 1;
-		const hashEnd = hashStart + HL_FILE_HASH_LENGTH;
-		if (hashEnd > end) return null;
-		for (let probe = hashStart; probe < hashEnd; probe++) {
+	const hashStart = end - HL_FILE_HASH_LENGTH - 1;
+	if (hashStart >= FILE_PREFIX_LENGTH && line.charCodeAt(hashStart) === CHAR_HASH) {
+		const tagStart = hashStart + 1;
+		for (let probe = tagStart; probe < end; probe++) {
 			if (!isHexDigitCode(line.charCodeAt(probe))) return null;
 		}
-		fileHash = line.slice(hashStart, hashEnd).toUpperCase();
-		index = hashEnd;
+		pathEnd = hashStart;
+		fileHash = line.slice(tagStart, end).toUpperCase();
 	}
-	if (skipWhitespace(line, index, end) !== end) return null;
+
+	if (pathEnd === FILE_PREFIX_LENGTH) return null;
+	const path = line.slice(FILE_PREFIX_LENGTH, pathEnd);
 	return fileHash !== undefined ? { path, fileHash } : { path };
 }
 
diff --git a/packages/hashline/test/leniency.test.ts b/packages/hashline/test/leniency.test.ts
index f2f2bb2aa..be8298fda 100644
--- a/packages/hashline/test/leniency.test.ts
+++ b/packages/hashline/test/leniency.test.ts
@@ -1,5 +1,5 @@
 import { describe, expect, it } from "bun:test";
-import { applyEdits, parsePatch } from "@oh-my-pi/hashline";
+import { applyEdits, Patch, parsePatch } from "@oh-my-pi/hashline";
 
 function applyPatch(text: string, diff: string): string {
 	return applyEdits(text, parsePatch(diff).edits).text;
@@ -7,6 +7,24 @@ function applyPatch(text: string, diff: string): string {
 
 const FILE = "a\nb\nc\nd\ne";
 
+describe("hashline section headers", () => {
+	it("accepts paths with spaces in anchored section headers", () => {
+		const section = Patch.parseSingle("¶dir with spaces/file.ts#1a2b\nreplace 1..1:\n+after");
+
+		expect(section.path).toBe("dir with spaces/file.ts");
+		expect(section.fileHash).toBe("1A2B");
+		expect(section.applyTo("before").text).toBe("after");
+	});
+
+	it("recovers apply_patch-contaminated headers whose paths contain spaces", () => {
+		const section = Patch.parseSingle("¶*** Update File: dir with spaces/file.ts#1A2B\nreplace 1..1:\n+after");
+
+		expect(section.path).toBe("dir with spaces/file.ts");
+		expect(section.fileHash).toBe("1A2B");
+		expect(section.applyTo("before").text).toBe("after");
+	});
+});
+
 describe("hashline core — verb header forms", () => {
 	it("rejects a bare single-number hunk header with verb guidance", () => {
 		expect(() => parsePatch("2\n+B")).toThrow(/hunk headers need a verb/);