diff --git a/hgext/journal.py b/hgext/journal.py
--- a/hgext/journal.py
+++ b/hgext/journal.py
@@ -36,8 +36,6 @@
     util,
 )
 
-from . import share
-
 cmdtable = {}
 command = registrar.command(cmdtable)
 
@@ -169,7 +167,7 @@
     """Copy shared journal entries into this repo when unsharing"""
     if (repo.path == repopath and repo.shared() and
             util.safehasattr(repo, 'journal')):
-        sharedrepo = share._getsrcrepo(repo)
+        sharedrepo = hg.sharedreposource(repo)
         sharedfeatures = _readsharedfeatures(repo)
         if sharedrepo and sharedfeatures > {'journal'}:
             # there is a shared repository and there are shared journal entries
@@ -258,7 +256,7 @@
         self.sharedfeatures = self.sharedvfs = None
         if repo.shared():
             features = _readsharedfeatures(repo)
-            sharedrepo = share._getsrcrepo(repo)
+            sharedrepo = hg.sharedreposource(repo)
             if sharedrepo is not None and 'journal' in features:
                 self.sharedvfs = sharedrepo.vfs
                 self.sharedfeatures = features
diff --git a/hgext/narrow/narrowrepo.py b/hgext/narrow/narrowrepo.py
--- a/hgext/narrow/narrowrepo.py
+++ b/hgext/narrow/narrowrepo.py
@@ -9,15 +9,12 @@
 
 from mercurial import (
     bundlerepo,
+    hg,
     localrepo,
     match as matchmod,
     scmutil,
 )
 
-from .. import (
-    share,
-)
-
 from . import (
     narrowrevlog,
     narrowspec,
@@ -37,7 +34,7 @@
 def unsharenarrowspec(orig, ui, repo, repopath):
     if (REQUIREMENT in repo.requirements
         and repo.path == repopath and repo.shared()):
-        srcrepo = share._getsrcrepo(repo)
+        srcrepo = hg.sharedreposource(repo)
         with srcrepo.vfs(narrowspec.FILENAME) as f:
             spec = f.read()
         with repo.vfs(narrowspec.FILENAME, 'w') as f:
diff --git a/hgext/narrow/narrowspec.py b/hgext/narrow/narrowspec.py
--- a/hgext/narrow/narrowspec.py
+++ b/hgext/narrow/narrowspec.py
@@ -12,14 +12,11 @@
 from mercurial.i18n import _
 from mercurial import (
     error,
+    hg,
     match as matchmod,
     util,
 )
 
-from .. import (
-    share,
-)
-
 FILENAME = 'narrowspec'
 
 def _parsestoredpatterns(text):
@@ -133,7 +130,7 @@
 
 def load(repo):
     if repo.shared():
-        repo = share._getsrcrepo(repo)
+        repo = hg.sharedreposource(repo)
     try:
         spec = repo.vfs.read(FILENAME)
     except IOError as e:
@@ -150,7 +147,7 @@
 def save(repo, includepats, excludepats):
     spec = format(includepats, excludepats)
     if repo.shared():
-        repo = share._getsrcrepo(repo)
+        repo = hg.sharedreposource(repo)
     repo.vfs.write(FILENAME, spec)
 
 def restrictpatterns(req_includes, req_excludes, repo_includes, repo_excludes):
diff --git a/hgext/share.py b/hgext/share.py
--- a/hgext/share.py
+++ b/hgext/share.py
@@ -52,9 +52,6 @@
     util,
 )
 
-repository = hg.repository
-parseurl = hg.parseurl
-
 cmdtable = {}
 command = registrar.command(cmdtable)
 # Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
@@ -135,27 +132,9 @@
         return False
     return hg.sharedbookmarks in shared
 
-def _getsrcrepo(repo):
-    """
-    Returns the source repository object for a given shared repository.
-    If repo is not a shared repository, return None.
-    """
-    if repo.sharedpath == repo.path:
-        return None
-
-    if util.safehasattr(repo, 'srcrepo') and repo.srcrepo:
-        return repo.srcrepo
-
-    # the sharedpath always ends in the .hg; we want the path to the repo
-    source = repo.vfs.split(repo.sharedpath)[0]
-    srcurl, branches = parseurl(source)
-    srcrepo = repository(repo.ui, srcurl)
-    repo.srcrepo = srcrepo
-    return srcrepo
-
 def getbkfile(orig, repo):
     if _hassharedbookmarks(repo):
-        srcrepo = _getsrcrepo(repo)
+        srcrepo = hg.sharedreposource(repo)
         if srcrepo is not None:
             # just orig(srcrepo) doesn't work as expected, because
             # HG_PENDING refers repo.root.
@@ -186,7 +165,7 @@
     orig(self, tr)
 
     if _hassharedbookmarks(self._repo):
-        srcrepo = _getsrcrepo(self._repo)
+        srcrepo = hg.sharedreposource(self._repo)
         if srcrepo is not None:
             category = 'share-bookmarks'
             tr.addpostclose(category, lambda tr: self._writerepo(srcrepo))
@@ -196,6 +175,6 @@
     orig(self, repo)
 
     if _hassharedbookmarks(self._repo):
-        srcrepo = _getsrcrepo(self._repo)
+        srcrepo = hg.sharedreposource(self._repo)
         if srcrepo is not None:
             orig(self, srcrepo)
diff --git a/mercurial/hg.py b/mercurial/hg.py
--- a/mercurial/hg.py
+++ b/mercurial/hg.py
@@ -202,6 +202,24 @@
         return ''
     return os.path.basename(os.path.normpath(path))
 
+def sharedreposource(repo):
+    """Returns repository object for source repository of a shared repo.
+
+    If repo is not a shared repository, returns None.
+    """
+    if repo.sharedpath == repo.path:
+        return None
+
+    if util.safehasattr(repo, 'srcrepo') and repo.srcrepo:
+        return repo.srcrepo
+
+    # the sharedpath always ends in the .hg; we want the path to the repo
+    source = repo.vfs.split(repo.sharedpath)[0]
+    srcurl, branches = parseurl(source)
+    srcrepo = repository(repo.ui, srcurl)
+    repo.srcrepo = srcrepo
+    return srcrepo
+
 def share(ui, source, dest=None, update=True, bookmarks=True, defaultpath=None,
           relative=False):
     '''create a shared repository'''