diff --git a/scripts/qapi/gen.py b/scripts/qapi/gen.py
index 2aec6d3436..aaed78eed5 100644
--- a/scripts/qapi/gen.py
+++ b/scripts/qapi/gen.py
@@ -295,23 +295,24 @@ class QAPISchemaModularCVisitor(QAPISchemaVisitor):
             genc.write(output_dir)
             genh.write(output_dir)
 
-    def _begin_system_module(self, name: None) -> None:
+    def _begin_builtin_module(self) -> None:
         pass
 
     def _begin_user_module(self, name: str) -> None:
         pass
 
     def visit_module(self, name: Optional[str]) -> None:
-        if name is None:
+        if QAPISchemaModule.is_builtin_module(name):
             if self._builtin_blurb:
-                self._add_system_module(None, self._builtin_blurb)
-                self._begin_system_module(name)
+                self._add_system_module(name, self._builtin_blurb)
+                self._begin_builtin_module()
             else:
                 # The built-in module has not been created.  No code may
                 # be generated.
                 self._genc = None
                 self._genh = None
         else:
+            assert QAPISchemaModule.is_user_module(name)
             self._add_user_module(name, self._user_blurb)
             self._begin_user_module(name)
 
diff --git a/scripts/qapi/types.py b/scripts/qapi/types.py
index 2b4916cdaa..dbf58c0b91 100644
--- a/scripts/qapi/types.py
+++ b/scripts/qapi/types.py
@@ -271,7 +271,7 @@ class QAPISchemaGenTypeVisitor(QAPISchemaModularCVisitor):
             prefix, 'qapi-types', ' * Schema-defined QAPI types',
             ' * Built-in QAPI types', __doc__)
 
-    def _begin_system_module(self, name: None) -> None:
+    def _begin_builtin_module(self) -> None:
         self._genc.preamble_add(mcgen('''
 #include "qemu/osdep.h"
 #include "qapi/dealloc-visitor.h"
diff --git a/scripts/qapi/visit.py b/scripts/qapi/visit.py
index 339f152152..568ba35592 100644
--- a/scripts/qapi/visit.py
+++ b/scripts/qapi/visit.py
@@ -305,7 +305,7 @@ class QAPISchemaGenVisitVisitor(QAPISchemaModularCVisitor):
             prefix, 'qapi-visit', ' * Schema-defined QAPI visitors',
             ' * Built-in QAPI visitors', __doc__)
 
-    def _begin_system_module(self, name: None) -> None:
+    def _begin_builtin_module(self) -> None:
         self._genc.preamble_add(mcgen('''
 #include "qemu/osdep.h"
 #include "qapi/error.h"