diff --git a/hgext/fix.py b/hgext/fix.py
--- a/hgext/fix.py
+++ b/hgext/fix.py
@@ -250,6 +250,7 @@
     """
     opts = pycompat.byteskwargs(opts)
     cmdutil.check_at_most_one_arg(opts, b'all', b'rev')
+    cmdutil.check_incompatible_arguments(opts, b'working_dir', [b'all'])
     if opts[b'all']:
         opts[b'rev'] = [b'not public() and not obsolete()']
         opts[b'working_dir'] = True
diff --git a/tests/test-fix-topology.t b/tests/test-fix-topology.t
--- a/tests/test-fix-topology.t
+++ b/tests/test-fix-topology.t
@@ -271,6 +271,9 @@
 
   $ hg init fixall
   $ cd fixall
+  $ hg fix --all --working-dir
+  abort: cannot specify both --working-dir and --all
+  [255]
 
 #if obsstore-on
   $ printf "one\n" > foo.whole