1 files changed, 1 insertions, 1 deletions

diff --git a/plugins/check_tcp.c b/plugins/check_tcp.c
index f464b15f..af3ae241 100644
--- a/plugins/check_tcp.c
+++ b/plugins/check_tcp.c
@@ -555,7 +555,7 @@ process_arguments (int argc, char **argv)
 #  ifdef USE_OPENSSL /* XXX */
                         if ((temp=strchr(optarg,','))!=NULL) {
                             *temp='\0';
-                            if (!is_intnonneg (temp))
+                            if (!is_intnonneg (optarg))
                                usage2 (_("Invalid certificate expiration period"), optarg);                              days_till_exp_warn = atoi(optarg);
                             *temp=',';
                             temp++;