diff --git a/Misc/NEWS b/Misc/NEWS
index e46b9a5774a..759ec4d9c5b 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -430,6 +430,9 @@ Tests
 Build
 -----
 
+- Issue #15923: fix a mistake in asdl_c.py that resulted in a TypeError after
+  2801bf875a24 (see #15801).
+
 - Issue #11715: Fix multiarch detection without having Debian development
   tools (dpkg-dev) installed.
 
diff --git a/Parser/asdl_c.py b/Parser/asdl_c.py
index 6a465490b6a..b6448c93def 100755
--- a/Parser/asdl_c.py
+++ b/Parser/asdl_c.py
@@ -1033,7 +1033,7 @@ class ObjVisitor(PickleVisitor):
             self.emit("case %s:" % t.name, 2)
             self.emit("Py_INCREF(%s_singleton);" % t.name, 3)
             self.emit("return %s_singleton;" % t.name, 3)
-        self.emit("default:" % name, 2)
+        self.emit("default:", 2)
         self.emit('/* should never happen, but just in case ... */', 3)
         code = "PyErr_Format(PyExc_SystemError, \"unknown %s found\");" % name
         self.emit(code, 3, reflow=False)