diff --git a/scripts/qapi/expr.py b/scripts/qapi/expr.py
index 4a3352a2bd..6b064a2138 100644
--- a/scripts/qapi/expr.py
+++ b/scripts/qapi/expr.py
@@ -16,8 +16,11 @@
 
 import re
 from typing import (
+    Iterable,
+    List,
     MutableMapping,
     Optional,
+    Union,
     cast,
 )
 
@@ -27,10 +30,11 @@
 from .source import QAPISourceInfo
 
 
-# Expressions in their raw form are JSON-like structures with arbitrary forms.
-# Minimally, their top-level form must be a mapping of strings to values.
-Expression = MutableMapping[str, object]
+# Arbitrary form for a JSON-like object.
+_JSObject = MutableMapping[str, object]
 
+# Expressions in their raw form are (just) JSON-like objects.
+Expression = _JSObject
 
 # Names must be letters, numbers, -, and _.  They must start with letter,
 # except for downstream extensions which must start with __RFQDN_.
@@ -39,14 +43,19 @@
                         '[a-zA-Z][a-zA-Z0-9_-]*$')
 
 
-def check_name_is_str(name, info, source):
+def check_name_is_str(name: object,
+                      info: QAPISourceInfo,
+                      source: str) -> None:
     if not isinstance(name, str):
         raise QAPISemError(info, "%s requires a string name" % source)
 
 
-def check_name_str(name, info, source,
-                   allow_optional=False, enum_member=False,
-                   permit_upper=False):
+def check_name_str(name: str,
+                   info: QAPISourceInfo,
+                   source: str,
+                   allow_optional: bool = False,
+                   enum_member: bool = False,
+                   permit_upper: bool = False) -> None:
     membername = name
 
     if allow_optional and name.startswith('*'):
@@ -66,16 +75,20 @@ def check_name_str(name, info, source,
     assert not membername.startswith('*')
 
 
-def check_defn_name_str(name, info, meta):
+def check_defn_name_str(name: str, info: QAPISourceInfo, meta: str) -> None:
     check_name_str(name, info, meta, permit_upper=True)
     if name.endswith('Kind') or name.endswith('List'):
         raise QAPISemError(
             info, "%s name should not end in '%s'" % (meta, name[-4:]))
 
 
-def check_keys(value, info, source, required, optional):
+def check_keys(value: _JSObject,
+               info: QAPISourceInfo,
+               source: str,
+               required: List[str],
+               optional: List[str]) -> None:
 
-    def pprint(elems):
+    def pprint(elems: Iterable[str]) -> str:
         return ', '.join("'" + e + "'" for e in sorted(elems))
 
     missing = set(required) - set(value)
@@ -95,7 +108,7 @@ def pprint(elems):
                pprint(unknown), pprint(allowed)))
 
 
-def check_flags(expr, info):
+def check_flags(expr: Expression, info: QAPISourceInfo) -> None:
     for key in ['gen', 'success-response']:
         if key in expr and expr[key] is not False:
             raise QAPISemError(
@@ -106,9 +119,9 @@ def check_flags(expr, info):
                 info, "flag '%s' may only use true value" % key)
 
 
-def check_if(expr, info, source):
+def check_if(expr: _JSObject, info: QAPISourceInfo, source: str) -> None:
 
-    def check_if_str(ifcond):
+    def check_if_str(ifcond: object) -> None:
         if not isinstance(ifcond, str):
             raise QAPISemError(
                 info,
@@ -134,7 +147,7 @@ def check_if_str(ifcond):
         expr['if'] = [ifcond]
 
 
-def normalize_members(members):
+def normalize_members(members: object) -> None:
     if isinstance(members, dict):
         for key, arg in members.items():
             if isinstance(arg, dict):
@@ -142,8 +155,11 @@ def normalize_members(members):
             members[key] = {'type': arg}
 
 
-def check_type(value, info, source,
-               allow_array=False, allow_dict=False):
+def check_type(value: Optional[object],
+               info: QAPISourceInfo,
+               source: str,
+               allow_array: bool = False,
+               allow_dict: Union[bool, str] = False) -> None:
     if value is None:
         return
 
@@ -187,7 +203,8 @@ def check_type(value, info, source,
         check_type(arg['type'], info, key_source, allow_array=True)
 
 
-def check_features(features, info):
+def check_features(features: Optional[object],
+                   info: QAPISourceInfo) -> None:
     if features is None:
         return
     if not isinstance(features, list):
@@ -204,7 +221,7 @@ def check_features(features, info):
         check_if(f, info, source)
 
 
-def check_enum(expr, info):
+def check_enum(expr: Expression, info: QAPISourceInfo) -> None:
     name = expr['enum']
     members = expr['data']
     prefix = expr.get('prefix')
@@ -228,7 +245,7 @@ def check_enum(expr, info):
         check_if(member, info, source)
 
 
-def check_struct(expr, info):
+def check_struct(expr: Expression, info: QAPISourceInfo) -> None:
     name = cast(str, expr['struct'])  # Asserted in check_exprs
     members = expr['data']
 
@@ -236,7 +253,7 @@ def check_struct(expr, info):
     check_type(expr.get('base'), info, "'base'")
 
 
-def check_union(expr, info):
+def check_union(expr: Expression, info: QAPISourceInfo) -> None:
     name = cast(str, expr['union'])  # Asserted in check_exprs
     base = expr.get('base')
     discriminator = expr.get('discriminator')
@@ -262,7 +279,7 @@ def check_union(expr, info):
         check_type(value['type'], info, source, allow_array=not base)
 
 
-def check_alternate(expr, info):
+def check_alternate(expr: Expression, info: QAPISourceInfo) -> None:
     members = expr['data']
 
     if not members:
@@ -279,7 +296,7 @@ def check_alternate(expr, info):
         check_type(value['type'], info, source)
 
 
-def check_command(expr, info):
+def check_command(expr: Expression, info: QAPISourceInfo) -> None:
     args = expr.get('data')
     rets = expr.get('returns')
     boxed = expr.get('boxed', False)
@@ -290,7 +307,7 @@ def check_command(expr, info):
     check_type(rets, info, "'returns'", allow_array=True)
 
 
-def check_event(expr, info):
+def check_event(expr: Expression, info: QAPISourceInfo) -> None:
     args = expr.get('data')
     boxed = expr.get('boxed', False)
 
@@ -299,7 +316,7 @@ def check_event(expr, info):
     check_type(args, info, "'data'", allow_dict=not boxed)
 
 
-def check_exprs(exprs):
+def check_exprs(exprs: List[_JSObject]) -> List[_JSObject]:
     for expr_elem in exprs:
         # Expression
         assert isinstance(expr_elem['expr'], dict)
diff --git a/scripts/qapi/mypy.ini b/scripts/qapi/mypy.ini
index 5ab3433c5f..0d0111930f 100644
--- a/scripts/qapi/mypy.ini
+++ b/scripts/qapi/mypy.ini
@@ -14,11 +14,6 @@ disallow_untyped_defs = False
 disallow_incomplete_defs = False
 check_untyped_defs = False
 
-[mypy-qapi.expr]
-disallow_untyped_defs = False
-disallow_incomplete_defs = False
-check_untyped_defs = False
-
 [mypy-qapi.parser]
 disallow_untyped_defs = False
 disallow_incomplete_defs = False
