diff --git a/swh/scrubber/db.py b/swh/scrubber/db.py
--- a/swh/scrubber/db.py
+++ b/swh/scrubber/db.py
@@ -131,8 +131,8 @@
         Returns the last date the given range was checked in the given datastore,
         or :const:`None` if it was never checked.
 
-        Currently, this checks range boundaries exactly, with no regard for ranges
-        that contain or are contained by it.
+        Currently, this matches range boundaries exactly, with no regard for
+        ranges that contain or are contained by it.
         """
         datastore_id = self.datastore_get_or_add(datastore)
         with self.transaction() as cur:
diff --git a/swh/scrubber/storage_checker.py b/swh/scrubber/storage_checker.py
--- a/swh/scrubber/storage_checker.py
+++ b/swh/scrubber/storage_checker.py
@@ -145,6 +145,26 @@
             )
 
             start_time = datetime.datetime.now(tz=datetime.timezone.utc)
+
+            # Currently, this matches range boundaries exactly, with no regard for
+            # ranges that contain or are contained by it.
+            last_check_time = self.db.checked_range_get_last_date(
+                self.datastore_info(),
+                range_start_swhid,
+                range_end_swhid,
+            )
+
+            if last_check_time is not None:
+                # TODO: re-check if 'last_check_time' was a long ago.
+                logger.debug(
+                    "Skipping processing of %s range %s to %s: already done at %s",
+                    self.object_type,
+                    backfill._format_range_bound(range_start),
+                    backfill._format_range_bound(range_end),
+                    last_check_time,
+                )
+                continue
+
             logger.debug(
                 "Processing %s range %s to %s",
                 self.object_type,
diff --git a/swh/scrubber/tests/test_storage_postgresql.py b/swh/scrubber/tests/test_storage_postgresql.py
--- a/swh/scrubber/tests/test_storage_postgresql.py
+++ b/swh/scrubber/tests/test_storage_postgresql.py
@@ -296,6 +296,47 @@
     assert_checked_ranges(scrubber_db, datastore, _long_ranges("snp"))
 
 
+@patch_byte_ranges
+def test_no_recheck(scrubber_db, datastore, swh_storage):
+    """
+    Tests that objects that were already checked are not checked again on
+    the next run.
+    """
+    # Corrupt two snapshots
+    snapshots = list(swh_model_data.SNAPSHOTS)
+    for i in (0, 1):
+        snapshots[i] = attr.evolve(snapshots[i], id=bytes([i]) * 20)
+    swh_storage.snapshot_add(snapshots)
+
+    # Mark ranges as already checked
+    now = datetime.datetime.now(tz=datetime.timezone.utc)
+    for (range_start, range_end) in EXPECTED_RANGES:
+        scrubber_db.checked_range_upsert(datastore, range_start, range_end, now)
+
+    StorageChecker(
+        db=scrubber_db,
+        storage=swh_storage,
+        object_type="snapshot",
+        start_object="00" * 20,
+        end_object="ff" * 20,
+    ).run()
+
+    corrupt_objects = list(scrubber_db.corrupt_object_iter())
+    assert (
+        corrupt_objects == []
+    ), "Detected corrupt objects in ranges that should have been skipped."
+
+    # Make sure the DB was not changed (in particular, that timestamps were not bumped)
+    ranges = [
+        (str(range_start), str(range_end), date)
+        for (range_start, range_end, date) in scrubber_db.checked_range_iter(datastore)
+    ]
+    ranges.sort(key=str)
+    assert ranges == [
+        (range_start, range_end, now) for (range_start, range_end) in EXPECTED_RANGES
+    ]
+
+
 @patch_byte_ranges
 def test_no_hole(scrubber_db, datastore, swh_storage):
     swh_storage.content_add([CONTENT1])