--- a/plis.c
+++ b/plis.c
@@ -443,9 +443,9 @@
                             if(!strncmp(argv[a], "pcon ", 5)) ChildPconTest(argv[a]);
                             
                             if(usesh)
-                                execl(SHELL, "sh", "-c", argv[a], NULL);
+                                execl(SHELL, "sh", "-c", argv[a], (char *) NULL);
                             else
-                                execlp(argv[a], NULL);
+                                execlp(argv[a], ";", (char *) NULL);
                         }
                         else
                         {