diff --git a/mercurial/bundle2.py b/mercurial/bundle2.py
--- a/mercurial/bundle2.py
+++ b/mercurial/bundle2.py
@@ -1323,7 +1323,8 @@ def getrepocaps(repo, allowpushback=Fals
         caps['obsmarkers'] = supportedformat
     if allowpushback:
         caps['pushback'] = ()
-    if not repo.ui.configbool('experimental', 'checkheads-strict', True):
+    cpmode = repo.ui.config('server', 'concurrent-push-mode', 'strict')
+    if cpmode == 'check-related':
         caps['checkheads'] = ('related',)
     return caps
 
diff --git a/mercurial/help/config.txt b/mercurial/help/config.txt
--- a/mercurial/help/config.txt
+++ b/mercurial/help/config.txt
@@ -1694,6 +1694,17 @@ Controls generic server settings.
     are highly recommended. Partial clones will still be allowed.
     (default: False)
 
+``concurrent-push-mode``
+    Level of allowed race condition between two pushing clients.
+
+    - 'strict': push is abort if another client touched the repository
+      while the push was preparing. (default)
+    - 'check-related': push is only aborted if it affects head that got also
+      affected while the push was preparing.
+
+    This requires compatible client (version 4.3 and later). Old client will
+    use 'strict'.
+
 ``validate``
     Whether to validate the completeness of pushed changesets by
     checking that all new file revisions specified in manifests are
diff --git a/tests/test-push-race.t b/tests/test-push-race.t
--- a/tests/test-push-race.t
+++ b/tests/test-push-race.t
@@ -111,8 +111,8 @@ We tests multiple cases:
 #if unrelated
 
   $ cat >> $HGRCPATH << EOF
-  > [experimental]
-  > checkheads-strict = no
+  > [server]
+  > concurrent-push-mode = check-related
   > EOF
 
 #endif