diff --git a/fragment.go b/fragment.go
index 3cd3659d3..5eda9e976 100644
--- a/fragment.go
+++ b/fragment.go
@@ -1639,88 +1639,43 @@ func (f *fragment) bulkImportMutex(rowIDs, columnIDs []uint64) error {
 	f.mu.Lock()
 	defer f.mu.Unlock()
 
-	// Disconnect op writer so we don't append updates.
-	f.storage.OpWriter = nil
-
-	// If an error occurs then reopen the storage.
-	if err := func() error {
-		// rowSet maintains the set of rowIDs present in this import.
-		// It allows the cache to be updated once per row, instead of once
-		// per bit.
-		rowSet := make(map[uint64]struct{})
-		lastRowID := uint64(0)
-
-		// Process every bit.
-		for i := range rowIDs {
-			rowID, columnID := rowIDs[i], columnIDs[i]
-
-			// Handle mutex vector (i.e. clear an existing row).
-			if existingRowID, found, err := f.mutexVector.Get(columnID); err != nil {
-				return errors.Wrap(err, "getting mutex vector data")
-			} else if found && existingRowID != rowID {
-				// Determine the position of the bit in the storage.
-				pos, err := f.pos(existingRowID, columnID)
-				if err != nil {
-					return err
-				}
-
-				// Clear storage.
-				_, err = f.storage.Remove(pos)
-				if err != nil {
-					return err
-				}
-
-				rowSet[existingRowID] = struct{}{}
-			}
-
+	rowSet := make(map[uint64]struct{})
+	// Since each imported bit will at most set one bit and clear one bit, we
+	// can reuse the rowIDs and columnIDs slices as the set and clear slice
+	// arguments to importPositions. We maintain indexes into them as we loop
+	// through them since the indexes of set and cleared bits may lag behind the
+	// current index.
+	setIdx := 0
+	clearIdx := 0
+	for i := range rowIDs {
+		rowID, columnID := rowIDs[i], columnIDs[i]
+		if existingRowID, found, err := f.mutexVector.Get(columnID); err != nil {
+			return errors.Wrap(err, "getting mutex vector data")
+		} else if found && existingRowID != rowID {
 			// Determine the position of the bit in the storage.
-			pos, err := f.pos(rowID, columnID)
+			clearPos, err := f.pos(existingRowID, columnID)
 			if err != nil {
 				return err
 			}
+			columnIDs[clearIdx] = clearPos
+			clearIdx++
 
-			// Write to storage.
-			_, err = f.storage.Add(pos)
-			if err != nil {
-				return err
-			}
-
-			// Reduce the StatsD rate for high volume stats
-			f.stats.Count("ImportBit", 1, 0.0001)
-
-			// Add row to rowSet.
-			if i == 0 || rowID != lastRowID {
-				lastRowID = rowID
-				rowSet[rowID] = struct{}{}
-			}
-
-			// Invalidate block checksum.
-			delete(f.checksums, int(rowID/HashBlockSize))
+			rowSet[existingRowID] = struct{}{}
+		} else if found && existingRowID == rowID {
+			continue
 		}
-
-		// Update cache counts for all rows.
-		for rowID := range rowSet {
-			// Import should ALWAYS have row() load a new bm from fragment.storage
-			// because the row that's in rowCache hasn't been updated with
-			// this import's data.
-			f.cache.BulkAdd(rowID, f.unprotectedRow(rowID).Count())
+		pos, err := f.pos(rowID, columnID)
+		if err != nil {
+			return err
 		}
-
-		f.cache.Invalidate()
-
-		return nil
-	}(); err != nil {
-		_ = f.closeStorage()
-		_ = f.openStorage()
-		return err
+		rowIDs[setIdx] = pos
+		setIdx++
+		rowSet[rowID] = struct{}{}
 	}
+	toSet := rowIDs[:setIdx]
+	toClear := columnIDs[:clearIdx]
 
-	// Write the storage to disk and reload.
-	if err := f.snapshot(); err != nil {
-		return err
-	}
-
-	return nil
+	return errors.Wrap(f.importPositions(toSet, toClear, rowSet), "importing positions")
 }
 
 // importValue bulk imports a set of range-encoded values.