diff --git a/hgext/fastannotate/protocol.py b/hgext/fastannotate/protocol.py
--- a/hgext/fastannotate/protocol.py
+++ b/hgext/fastannotate/protocol.py
@@ -101,7 +101,7 @@ def _registerwireprotocommand():
 
 def serveruisetup(ui):
     _registerwireprotocommand()
-    extensions.wrapfunction(wireprotov1server, b'_capabilities', _capabilities)
+    extensions.wrapfunction(wireprotov1server, '_capabilities', _capabilities)
 
 
 # client-side
diff --git a/hgext/fastannotate/support.py b/hgext/fastannotate/support.py
--- a/hgext/fastannotate/support.py
+++ b/hgext/fastannotate/support.py
@@ -129,8 +129,8 @@ def _remotefctxannotate(orig, self, foll
 
 
 def replacehgwebannotate():
-    extensions.wrapfunction(hgweb.webutil, b'annotate', _hgwebannotate)
+    extensions.wrapfunction(hgweb.webutil, 'annotate', _hgwebannotate)
 
 
 def replacefctxannotate():
-    extensions.wrapfunction(hgcontext.basefilectx, b'annotate', _fctxannotate)
+    extensions.wrapfunction(hgcontext.basefilectx, 'annotate', _fctxannotate)