diff --git a/src/dosinst.c b/src/dosinst.c
index 608f381..e77152f 100644
--- a/src/dosinst.c
+++ b/src/dosinst.c
@@ -2495,7 +2495,7 @@
 	    int vimfiles_dir_choice = (int)vimfiles_dir_none;
 
 	    init_directories_choice();
-	    if (argv[i + 1][0] != '-')
+	    if (i + 1 < argc && argv[i + 1][0] != '-')
 	    {
 		i++;
 		if (strcmp(argv[i], "vim") == 0)