diff --git a/b2/_internal/_cli/autocomplete_install.py b/b2/_internal/_cli/autocomplete_install.py
index 175d4945..3273916e 100644
--- a/b2/_internal/_cli/autocomplete_install.py
+++ b/b2/_internal/_cli/autocomplete_install.py
@@ -201,6 +201,9 @@ def is_enabled(self) -> bool:
         """
         environ = os.environ.copy()
         environ.setdefault("TERM", "xterm")  # TERM has to be set for fish to load completions
+        _silent_success_run_with_tty(
+            [self.shell_exec, '-c', f'complete -C {quote(self.prog)}']
+        )
         return _silent_success_run_with_tty(
             [
                 self.shell_exec, '-i', '-c',