diff --git a/.gitignore b/.gitignore
index 27e8dfb..000826d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -51,6 +51,7 @@ tests/skill_engine/*
 !tests/skill_engine/test_evolver_length_recovery.py
 !tests/skill_engine/test_evolution_retry_idempotency.py
 !tests/skill_engine/test_analyzer_length_recovery.py
+!tests/skill_engine/test_detect_patch_type_prose.py
 !tests/skill_engine/decision/
 tests/skill_engine/decision/*
 !tests/skill_engine/decision/test_analysis_adapter.py
diff --git a/tests/skill_engine/test_detect_patch_type_prose.py b/tests/skill_engine/test_detect_patch_type_prose.py
new file mode 100644
index 0000000..98c04fe
--- /dev/null
+++ b/tests/skill_engine/test_detect_patch_type_prose.py
@@ -0,0 +1,38 @@
+"""Regression: mid-document *** File: prose must not drop SKILL.md."""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+from openspace.skill_engine.patch import (
+    PatchType,
+    create_skill,
+    detect_patch_type,
+    parse_multi_file_full,
+)
+
+
+def test_detect_patch_type_ignores_single_mid_document_file_marker():
+    content = "# My Skill\n\n*** File: helper.sh\n#!/bin/bash\necho hi\n"
+    assert detect_patch_type(content) == PatchType.FULL
+    parsed = parse_multi_file_full(content)
+    assert list(parsed.keys()) == ["SKILL.md"]
+    assert "*** File: helper.sh" in parsed["SKILL.md"]
+
+
+def test_create_skill_keeps_skill_md_when_file_marker_is_prose(tmp_path: Path):
+    content = "# My Skill\n\n*** File: helper.sh\n#!/bin/bash\necho hi\n"
+    result = create_skill(tmp_path / "s", content)
+    assert result.ok
+    skill_md = tmp_path / "s" / "SKILL.md"
+    assert skill_md.is_file()
+    assert "*** File: helper.sh" in skill_md.read_text()
+    assert not (tmp_path / "s" / "helper.sh").exists()
+
+
+def test_detect_patch_type_accepts_structural_multi_file_at_start():
+    content = "*** File: SKILL.md\n# Skill\n\n*** File: helper.sh\n#!/bin/bash\necho hi\n"
+    assert detect_patch_type(content) == PatchType.FULL
+    parsed = parse_multi_file_full(content)
+    assert "SKILL.md" in parsed
+    assert "helper.sh" in parsed