---
 pgpewrap.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- pgpewrap.c
+++ pgpewrap.c	2017-09-11 11:34:11.241263407 +0000
@@ -63,6 +63,12 @@ int main(int argc, char **argv)
   }
   *opt = NULL;
 
+  if (opts[0] == NULL)
+  {
+    fprintf(stderr, "Command line usage: %s [flags] -- prefix [recipients]\n", argv[0]);
+    return 1;
+  }
+
   execvp(opts[0], opts);
   perror(argv[0]);
   return 2;