diff --git a/cmds-scrub.c b/cmds-scrub.c
index 8655d3d9..31ace6d4 100644
--- a/cmds-scrub.c
+++ b/cmds-scrub.c
@@ -1192,6 +1192,7 @@ static int scrub_start(int argc, char **argv, int resume)
 			/* ... yes, so scrub must be running. error out */
 			fprintf(stderr, "ERROR: scrub already running\n");
 			close(prg_fd);
+			prg_fd = -1;
 			goto out;
 		}
 		/*