#include "cache.h"
 #include "run-command.h"
+#include "exec_cmd.h"
 
 static const char *pgm;
 static const char *arguments[9];
        signal(SIGCHLD, SIG_DFL);
 
        if (argc < 3)
-               usage("git-merge-index [-o] [-q] <merge-program> (-a | [--] <filename>*)");
+               usage("git merge-index [-o] [-q] <merge-program> (-a | [--] <filename>*)");
+
+       git_extract_argv0_path(argv[0]);
 
        setup_git_directory();
        read_cache();