diff --git a/backend/handler/scan_handler.py b/backend/handler/scan_handler.py
index 7b6d8e6ea..9179831cf 100644
--- a/backend/handler/scan_handler.py
+++ b/backend/handler/scan_handler.py
@@ -682,6 +682,14 @@ async def fetch_hltb_rom() -> HLTBRom:
                 )
             )
         ):
+            # A refresh keeps the ID already on the ROM, often a manual match,
+            # rather than trading it for a filename guess. COMPLETE rematches.
+            if rom.hltb_id and (
+                scan_type == ScanType.UPDATE
+                or (scan_type == ScanType.UNMATCHED and not rom.hltb_metadata)
+            ):
+                return await meta_hltb_handler.get_rom_by_id(rom.hltb_id)
+
             return await meta_hltb_handler.get_rom(rom_attrs["fs_name"], platform.slug)
 
         return HLTBRom(hltb_id=None)
diff --git a/backend/tests/handler/test_scan_hltb_match.py b/backend/tests/handler/test_scan_hltb_match.py
new file mode 100644
index 000000000..dfbbcc276
--- /dev/null
+++ b/backend/tests/handler/test_scan_hltb_match.py
@@ -0,0 +1,143 @@
+"""How a scan picks a ROM's HowLongToBeat match.
+
+The filename lookup matches fuzzily, so re-running it on a ROM that already
+carries an ID lets a different game outscore a match the user pinned by hand.
+"""
+
+from types import SimpleNamespace
+from unittest.mock import AsyncMock, patch
+
+import pytest
+
+from handler.database import db_platform_handler, db_rom_handler
+from handler.metadata.hltb_handler import HLTBMetadata, HLTBRom
+from handler.scan_handler import MetadataSource, ScanType, scan_rom
+from models.platform import Platform
+from models.rom import Rom
+from utils.context import initialize_context
+
+FS_NAME = "Mario Kart 64 (USA).z64"
+PINNED = HLTBRom(hltb_id=2255, name="Mario Kart 64")
+GUESSED = HLTBRom(hltb_id=9999, name="Mario Kart 8")
+NO_MATCH = HLTBRom(hltb_id=None)
+
+
+@pytest.fixture
+def lookups():
+    """Patch both HowLongToBeat lookups, defaulting each to a miss."""
+    with (
+        patch(
+            "handler.scan_handler.meta_hltb_handler.get_rom_by_id",
+            new=AsyncMock(return_value=NO_MATCH),
+        ) as by_id,
+        patch(
+            "handler.scan_handler.meta_hltb_handler.get_rom",
+            new=AsyncMock(return_value=NO_MATCH),
+        ) as by_name,
+    ):
+        yield SimpleNamespace(by_id=by_id, by_name=by_name)
+
+
+async def _scan(
+    scan_type: ScanType,
+    hltb_id: int | None = None,
+    hltb_metadata: HLTBMetadata | None = None,
+) -> Rom:
+    platform = db_platform_handler.add_platform(
+        Platform(id=1, slug="n64", fs_slug="n64", name="Nintendo 64")
+    )
+    rom = db_rom_handler.add_rom(
+        Rom(
+            platform_id=platform.id,
+            fs_name=FS_NAME,
+            fs_name_no_tags="Mario Kart 64",
+            fs_name_no_ext="Mario Kart 64 (USA)",
+            fs_extension="z64",
+            fs_path="n64",
+            name="Mario Kart 64",
+            hltb_id=hltb_id,
+            hltb_metadata=dict(hltb_metadata or {}),
+            fs_size_bytes=1024,
+            tags=[],
+        )
+    )
+
+    async with initialize_context():
+        return await scan_rom(
+            platform=platform,
+            scan_type=scan_type,
+            rom=rom,
+            fs_rom={
+                "fs_name": FS_NAME,
+                "flat": True,
+                "nested": False,
+                "files": [],
+                "crc_hash": "",
+                "md5_hash": "",
+                "sha1_hash": "",
+                "ra_hash": "",
+            },
+            metadata_sources=[MetadataSource.HLTB],
+            newly_added=False,
+        )
+
+
+async def test_no_stored_id_uses_the_file_name_lookup(lookups):
+    lookups.by_name.return_value = GUESSED
+
+    result = await _scan(ScanType.COMPLETE)
+
+    lookups.by_id.assert_not_awaited()
+    lookups.by_name.assert_awaited_once_with(FS_NAME, "n64")
+    assert result.hltb_id == 9999
+
+
+async def test_complete_rescan_rematches_a_stored_id(lookups):
+    """A complete rescan wipes external IDs by design, so it re-runs the search."""
+    lookups.by_name.return_value = GUESSED
+
+    result = await _scan(ScanType.COMPLETE, hltb_id=2255)
+
+    lookups.by_id.assert_not_awaited()
+    lookups.by_name.assert_awaited_once_with(FS_NAME, "n64")
+    assert result.hltb_id == 9999
+
+
+async def test_update_scan_refetches_a_stored_id(lookups):
+    """A pinned match is refreshed by ID, never re-guessed from the filename."""
+    lookups.by_id.return_value = PINNED
+
+    result = await _scan(
+        ScanType.UPDATE, hltb_id=2255, hltb_metadata=HLTBMetadata(release_year=1997)
+    )
+
+    lookups.by_id.assert_awaited_once_with(2255)
+    lookups.by_name.assert_not_awaited()
+    assert result.hltb_id == 2255
+
+
+async def test_stored_id_is_not_replaced_by_a_file_name_guess(lookups):
+    """An ID the provider can't resolve stays put rather than being re-guessed."""
+    await _scan(ScanType.UPDATE, hltb_id=2255)
+
+    lookups.by_id.assert_awaited_once_with(2255)
+    lookups.by_name.assert_not_awaited()
+
+
+async def test_unmatched_scan_refetches_metadata_for_a_stored_id(lookups):
+    lookups.by_id.return_value = PINNED
+
+    result = await _scan(ScanType.UNMATCHED, hltb_id=2255)
+
+    lookups.by_id.assert_awaited_once_with(2255)
+    lookups.by_name.assert_not_awaited()
+    assert result.hltb_id == 2255
+
+
+async def test_unmatched_scan_without_a_stored_id_uses_the_file_name_lookup(lookups):
+    lookups.by_name.return_value = GUESSED
+
+    await _scan(ScanType.UNMATCHED)
+
+    lookups.by_id.assert_not_awaited()
+    lookups.by_name.assert_awaited_once_with(FS_NAME, "n64")