diff --git a/main.py b/main.py
index adfaffb..a5979a8 100755
--- a/main.py
+++ b/main.py
@@ -42,6 +42,7 @@
 from git_config import init_ssh, close_ssh
 from command import InteractiveCommand
 from command import MirrorSafeCommand
+from command import RequiresGitcCommand
 from subcmds.version import Version
 from editor import Editor
 from error import DownloadError
@@ -143,6 +144,11 @@
             file=sys.stderr)
       return 1
 
+    if isinstance(cmd, RequiresGitcCommand) and not gitc_utils.get_gitc_manifest_dir():
+      print("fatal: '%s' requires GITC to be available" % name,
+            file=sys.stderr)
+      return 1
+
     try:
       copts, cargs = cmd.OptionParser.parse_args(argv)
       copts = cmd.ReadEnvironmentOptions(copts)