diff --git a/Lib/test/test_gdb.py b/Lib/test/test_gdb.py
index dbcb5983e9b..3127e69ca9b 100644
--- a/Lib/test/test_gdb.py
+++ b/Lib/test/test_gdb.py
@@ -887,7 +887,7 @@ id(42)
                                           breakpoint='time_gmtime',
                                           cmds_after_breakpoint=['py-bt-full'],
                                           )
-        self.assertIn('#2 <built-in method gmtime', gdb_output)
+        self.assertIn('#1 <built-in method gmtime', gdb_output)
 
     @unittest.skipIf(python_is_optimized(),
                      "Python was compiled with optimizations")
diff --git a/Tools/gdb/libpython.py b/Tools/gdb/libpython.py
index d744cab7642..d49546fa9c4 100755
--- a/Tools/gdb/libpython.py
+++ b/Tools/gdb/libpython.py
@@ -1564,7 +1564,8 @@ class Frame(object):
             return False
 
         if caller in ('_PyCFunction_FastCallDict',
-                      '_PyCFunction_FastCallKeywords'):
+                      '_PyCFunction_FastCallKeywords',
+                      'cfunction_call_varargs'):
             arg_name = 'func'
             # Within that frame:
             #   "func" is the local containing the PyObject* of the