diff --git a/pgrep.c b/pgrep.c
index 6c70112b..bf102be7 100644
--- a/pgrep.c
+++ b/pgrep.c
@@ -549,16 +549,18 @@ static struct el * select_procs (int *num)
 
         if (opt_long || opt_longlong || (match && opt_pattern)) {
             if (opt_longlong)
-                strncpy (cmdoutput, task_cmdline, CMDSTRSIZE-1);
+                strncpy (cmdoutput, task_cmdline, sizeof cmdoutput -1);
             else
-                strncpy (cmdoutput, PIDS_GETSTR(CMD), CMDSTRSIZE-1);
+                strncpy (cmdoutput, PIDS_GETSTR(CMD), sizeof cmdoutput -1);
+            cmdoutput[sizeof cmdoutput - 1] = '\0';
         }
 
         if (match && opt_pattern) {
             if (opt_full)
-                strncpy (cmdsearch, task_cmdline, CMDSTRSIZE-1);
+                strncpy (cmdsearch, task_cmdline, sizeof cmdsearch -1);
             else
-                strncpy (cmdsearch, PIDS_GETSTR(CMD), CMDSTRSIZE-1);
+                strncpy (cmdsearch, PIDS_GETSTR(CMD), sizeof cmdsearch -1);
+            cmdsearch[sizeof cmdsearch - 1] = '\0';
 
             if (regexec (preg, cmdsearch, 0, NULL, 0) != 0)
                 match = 0;