diff --git a/scripts/qapi/commands.py b/scripts/qapi/commands.py
index 389dd879a6..80f22d562d 100644
--- a/scripts/qapi/commands.py
+++ b/scripts/qapi/commands.py
@@ -13,19 +13,32 @@
 See the COPYING file in the top-level directory.
 """
 
+from typing import Dict, Optional, List, Set
+
 from .common import (
     c_name,
     mcgen,
 )
 from .gen import (
+    QAPIGenC,
     QAPIGenCCode,
     QAPISchemaModularCVisitor,
     build_params,
     ifcontext,
 )
+from .schema import (
+    QAPISchema,
+    QAPISchemaFeature,
+    QAPISchemaObjectType,
+    QAPISchemaType,
+)
+from .source import QAPISourceInfo
 
 
-def gen_command_decl(name, arg_type, boxed, ret_type):
+def gen_command_decl(name: str,
+                     arg_type: Optional[QAPISchemaObjectType],
+                     boxed: bool,
+                     ret_type: Optional[QAPISchemaType]) -> str:
     return mcgen('''
 %(c_type)s qmp_%(c_name)s(%(params)s);
 ''',
@@ -34,7 +47,10 @@ def gen_command_decl(name, arg_type, boxed, ret_type):
                  params=build_params(arg_type, boxed, 'Error **errp'))
 
 
-def gen_call(name, arg_type, boxed, ret_type):
+def gen_call(name: str,
+             arg_type: Optional[QAPISchemaObjectType],
+             boxed: bool,
+             ret_type: Optional[QAPISchemaType]) -> str:
     ret = ''
 
     argstr = ''
@@ -70,7 +86,7 @@ def gen_call(name, arg_type, boxed, ret_type):
     return ret
 
 
-def gen_marshal_output(ret_type):
+def gen_marshal_output(ret_type: QAPISchemaType) -> str:
     return mcgen('''
 
 static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in,
@@ -91,19 +107,22 @@ def gen_marshal_output(ret_type):
                  c_type=ret_type.c_type(), c_name=ret_type.c_name())
 
 
-def build_marshal_proto(name):
+def build_marshal_proto(name: str) -> str:
     return ('void qmp_marshal_%s(QDict *args, QObject **ret, Error **errp)'
             % c_name(name))
 
 
-def gen_marshal_decl(name):
+def gen_marshal_decl(name: str) -> str:
     return mcgen('''
 %(proto)s;
 ''',
                  proto=build_marshal_proto(name))
 
 
-def gen_marshal(name, arg_type, boxed, ret_type):
+def gen_marshal(name: str,
+                arg_type: Optional[QAPISchemaObjectType],
+                boxed: bool,
+                ret_type: Optional[QAPISchemaType]) -> str:
     have_args = boxed or (arg_type and not arg_type.is_empty())
 
     ret = mcgen('''
@@ -185,7 +204,10 @@ def gen_marshal(name, arg_type, boxed, ret_type):
     return ret
 
 
-def gen_register_command(name, success_response, allow_oob, allow_preconfig):
+def gen_register_command(name: str,
+                         success_response: bool,
+                         allow_oob: bool,
+                         allow_preconfig: bool) -> str:
     options = []
 
     if not success_response:
@@ -207,7 +229,7 @@ def gen_register_command(name, success_response, allow_oob, allow_preconfig):
     return ret
 
 
-def gen_registry(registry, prefix):
+def gen_registry(registry: str, prefix: str) -> str:
     ret = mcgen('''
 
 void %(c_prefix)sqmp_init_marshal(QmpCommandList *cmds)
@@ -224,15 +246,14 @@ def gen_registry(registry, prefix):
 
 
 class QAPISchemaGenCommandVisitor(QAPISchemaModularCVisitor):
-
-    def __init__(self, prefix):
+    def __init__(self, prefix: str):
         super().__init__(
             prefix, 'qapi-commands',
             ' * Schema-defined QAPI/QMP commands', None, __doc__)
         self._regy = QAPIGenCCode(None)
-        self._visited_ret_types = {}
+        self._visited_ret_types: Dict[QAPIGenC, Set[QAPISchemaType]] = {}
 
-    def _begin_user_module(self, name):
+    def _begin_user_module(self, name: str) -> None:
         self._visited_ret_types[self._genc] = set()
         commands = self._module_basename('qapi-commands', name)
         types = self._module_basename('qapi-types', name)
@@ -256,7 +277,7 @@ def _begin_user_module(self, name):
 ''',
                              types=types))
 
-    def visit_end(self):
+    def visit_end(self) -> None:
         self._add_system_module('init', ' * QAPI Commands initialization')
         self._genh.add(mcgen('''
 #include "qapi/qmp/dispatch.h"
@@ -272,9 +293,18 @@ def visit_end(self):
                                       prefix=self._prefix))
         self._genc.add(gen_registry(self._regy.get_content(), self._prefix))
 
-    def visit_command(self, name, info, ifcond, features,
-                      arg_type, ret_type, gen, success_response, boxed,
-                      allow_oob, allow_preconfig):
+    def visit_command(self,
+                      name: str,
+                      info: QAPISourceInfo,
+                      ifcond: List[str],
+                      features: List[QAPISchemaFeature],
+                      arg_type: Optional[QAPISchemaObjectType],
+                      ret_type: Optional[QAPISchemaType],
+                      gen: bool,
+                      success_response: bool,
+                      boxed: bool,
+                      allow_oob: bool,
+                      allow_preconfig: bool) -> None:
         if not gen:
             return
         # FIXME: If T is a user-defined type, the user is responsible
@@ -295,7 +325,9 @@ def visit_command(self, name, info, ifcond, features,
                                                 allow_oob, allow_preconfig))
 
 
-def gen_commands(schema, output_dir, prefix):
+def gen_commands(schema: QAPISchema,
+                 output_dir: str,
+                 prefix: str) -> None:
     vis = QAPISchemaGenCommandVisitor(prefix)
     schema.visit(vis)
     vis.write(output_dir)
