diff --git a/mercurial/dispatch.py b/mercurial/dispatch.py
--- a/mercurial/dispatch.py
+++ b/mercurial/dispatch.py
@@ -583,7 +583,7 @@ def _dispatch(req):
         raise util.Abort(_("option --cwd may not be abbreviated!"))
     if options["repository"]:
         raise util.Abort(_(
-            "Option -R has to be separated from other options (e.g. not -qR) "
+            "option -R has to be separated from other options (e.g. not -qR) "
             "and --repository may only be abbreviated as --repo!"))
 
     if options["encoding"]:
diff --git a/tests/test-globalopts.t b/tests/test-globalopts.t
--- a/tests/test-globalopts.t
+++ b/tests/test-globalopts.t
@@ -136,16 +136,16 @@ earlygetopt with illegal abbreviations:
   abort: option --cwd may not be abbreviated!
   [255]
   $ hg --rep a tip
-  abort: Option -R has to be separated from other options (e.g. not -qR) and --repository may only be abbreviated as --repo!
+  abort: option -R has to be separated from other options (e.g. not -qR) and --repository may only be abbreviated as --repo!
   [255]
   $ hg --repositor a tip
-  abort: Option -R has to be separated from other options (e.g. not -qR) and --repository may only be abbreviated as --repo!
+  abort: option -R has to be separated from other options (e.g. not -qR) and --repository may only be abbreviated as --repo!
   [255]
   $ hg -qR a tip
-  abort: Option -R has to be separated from other options (e.g. not -qR) and --repository may only be abbreviated as --repo!
+  abort: option -R has to be separated from other options (e.g. not -qR) and --repository may only be abbreviated as --repo!
   [255]
   $ hg -qRa tip
-  abort: Option -R has to be separated from other options (e.g. not -qR) and --repository may only be abbreviated as --repo!
+  abort: option -R has to be separated from other options (e.g. not -qR) and --repository may only be abbreviated as --repo!
   [255]
 
 Testing --cwd: