diff --git a/src/pg_probackup.h b/src/pg_probackup.h
index 39e2db67..55a00636 100644
--- a/src/pg_probackup.h
+++ b/src/pg_probackup.h
@@ -112,7 +112,7 @@ typedef struct pgFile
 
 /* Special values of datapagemap_t bitmapsize */
 #define PageBitmapIsEmpty 0		/* Used to mark unchanged datafiles */
-#define PageBitmapIsAbsent -1	/* Used to mark files with unknown state of pagemap, i.e. datafiles without _ptrack */
+#define PageBitmapIsAbsent 0	/* Used to mark files with unknown state of pagemap, i.e. datafiles without _ptrack */
 
 /* Current state of backup */
 typedef enum BackupStatus