diff --git a/gclient.py b/gclient.py
index 471f431ff..ad0037d53 100755
--- a/gclient.py
+++ b/gclient.py
@@ -2273,6 +2273,8 @@ def CMDflatten(parser, args):
   options.nohooks = True
   options.process_all_deps = True
   client = GClient.LoadCurrentConfig(options)
+  if not client:
+    raise gclient_utils.Error('client not configured; see \'gclient config\'')
 
   # Only print progress if we're writing to a file. Otherwise, progress updates
   # could obscure intended output.
@@ -2758,6 +2760,8 @@ def CMDvalidate(parser, args):
   """Validates the .gclient and DEPS syntax."""
   options, args = parser.parse_args(args)
   client = GClient.LoadCurrentConfig(options)
+  if not client:
+    raise gclient_utils.Error('client not configured; see \'gclient config\'')
   rv = client.RunOnDeps('validate', args)
   if rv == 0:
     print('validate: SUCCESS')