diff --git a/grub-core/lib/arg.c b/grub-core/lib/arg.c
index 8439a0062..ade82d5dc 100644
--- a/grub-core/lib/arg.c
+++ b/grub-core/lib/arg.c
@@ -299,6 +299,19 @@ grub_arg_parse (grub_extcmd_t cmd, int argc, char **argv,
 		 it can have an argument value.  */
 	      if (*curshort)
 		{
+		  /*
+		   * Only permit further short opts if this one doesn't
+		   * require a value.
+		   */
+		  if (opt->type != ARG_TYPE_NONE &&
+		      !(opt->flags & GRUB_ARG_OPTION_OPTIONAL))
+		    {
+		      grub_error (GRUB_ERR_BAD_ARGUMENT,
+				  N_("missing mandatory option for `%s'"),
+				  opt->longarg);
+		      goto fail;
+		    }
+
 		  if (parse_option (cmd, opt, 0, usr) || grub_errno)
 		    goto fail;
 		}