diff --git a/mercurial/bookmarks.py b/mercurial/bookmarks.py
--- a/mercurial/bookmarks.py
+++ b/mercurial/bookmarks.py
@@ -17,6 +17,7 @@ from .node import (
 )
 from . import (
     encoding,
+    error,
     lock as lockmod,
     obsolete,
     util,
@@ -154,7 +155,10 @@ class bmstore(dict):
 
     def expandname(self, bname):
         if bname == '.':
-            return self.active
+            if self.active:
+                return self.active
+            else:
+                raise error.Abort(_("no active bookmark"))
         return bname
 
 def _readactive(repo, marks):
diff --git a/tests/test-bookmarks-pushpull.t b/tests/test-bookmarks-pushpull.t
--- a/tests/test-bookmarks-pushpull.t
+++ b/tests/test-bookmarks-pushpull.t
@@ -113,6 +113,19 @@ export the active bookmark
   exporting bookmark V
   [1]
 
+exporting the active bookmark with 'push -B .'
+demand that one of the bookmarks is activated
+
+  $ hg update -r default
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  (leaving bookmark V)
+  $ hg push -B . ../a
+  abort: no active bookmark
+  [255]
+  $ hg update -r V
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  (activating bookmark V)
+
 delete the bookmark
 
   $ hg book -d V