diff --git a/drivers/staging/lustre/lustre/libcfs/tracefile.c b/drivers/staging/lustre/lustre/libcfs/tracefile.c
index 07845e844243..f883030ad972 100644
--- a/drivers/staging/lustre/lustre/libcfs/tracefile.c
+++ b/drivers/staging/lustre/lustre/libcfs/tracefile.c
@@ -767,7 +767,7 @@ int cfs_trace_copyin_string(char *knl_buffer, int knl_buffer_nob,
 		return -EFAULT;
 
 	nob = strnlen(knl_buffer, usr_buffer_nob);
-	while (nob-- >= 0)		      /* strip trailing whitespace */
+	while (--nob >= 0)		      /* strip trailing whitespace */
 		if (!isspace(knl_buffer[nob]))
 			break;