diff --git a/scripts/qapi.py b/scripts/qapi.py
index f6701f5..96fb216 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -1000,7 +1000,6 @@ class QAPISchemaObjectType(QAPISchemaType):
         return self.name.startswith('q_')

     def c_name(self):
-        assert not self.is_implicit()
         return QAPISchemaType.c_name(self)

     def c_type(self):
@@ -1008,7 +1007,6 @@ class QAPISchemaObjectType(QAPISchemaType):
         return c_name(self.name) + pointer_suffix

     def c_unboxed_type(self):
-        assert not self.is_implicit()
         return c_name(self.name)

     def json_type(self):
diff --git a/scripts/qapi-types.py b/scripts/qapi-types.py
index f194bea..79416b2 100644
--- a/scripts/qapi-types.py
+++ b/scripts/qapi-types.py
@@ -61,8 +61,7 @@ def gen_object(name, base, members, variants):
     ret = ''
     if variants:
         for v in variants.variants:
-            if (isinstance(v.type, QAPISchemaObjectType) and
-                    not v.type.is_implicit()):
+            if isinstance(v.type, QAPISchemaObjectType):
                 ret += gen_object(v.type.name, v.type.base,
                                   v.type.local_members, v.type.variants)

@@ -180,6 +179,8 @@ class QAPISchemaGenTypeVisitor(QAPISchemaVisitor):
         self._btin = None

     def visit_begin(self, schema):
+        # gen_object() is recursive, ensure it doesn't visit the empty type
+        objects_seen.add(schema.the_empty_object_type.name)
         self.decl = ''
         self.defn = ''
         self._fwdecl = ''
@@ -196,11 +197,6 @@ class QAPISchemaGenTypeVisitor(QAPISchemaVisitor):
         self.decl = self._btin + self.decl
         self._btin = None

-    def visit_needed(self, entity):
-        # Visit everything except implicit objects
-        return not (entity.is_implicit() and
-                    isinstance(entity, QAPISchemaObjectType))
-
     def _gen_type_cleanup(self, name):
         self.decl += gen_type_cleanup_decl(name)
         self.defn += gen_type_cleanup(name)
@@ -229,11 +225,18 @@ class QAPISchemaGenTypeVisitor(QAPISchemaVisitor):
             self._gen_type_cleanup(name)

     def visit_object_type(self, name, info, base, members, variants):
+        # Nothing to do for the special empty builtin
+        if name == 'q_empty':
+            return
         self._fwdecl += gen_fwd_object_or_array(name)
         self.decl += gen_object(name, base, members, variants)
         if base:
             self.decl += gen_upcast(name, base)
-        self._gen_type_cleanup(name)
+        # TODO Worth changing the visitor signature, so we could
+        # directly use rather than repeat type.is_implicit()?
+        if not name.startswith('q_'):
+            # implicit types won't be directly allocated/freed
+            self._gen_type_cleanup(name)

     def visit_alternate_type(self, name, info, variants):
         self._fwdecl += gen_fwd_object_or_array(name)
diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
index a712e9a..4923b2e 100644
--- a/scripts/qapi-visit.py
+++ b/scripts/qapi-visit.py
@@ -215,13 +215,11 @@ out:


 def gen_visit_object(name, base, members, variants):
-    ret = gen_visit_object_members(name, base, members, variants)
-
     # FIXME: if *obj is NULL on entry, and visit_start_struct() assigns to
     # *obj, but then visit_type_FOO_members() fails, we should clean up *obj
     # rather than leaving it non-NULL. As currently written, the caller must
     # call qapi_free_FOO() to avoid a memory leak of the partial FOO.
-    ret += mcgen('''
+    return mcgen('''

 void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
 {
@@ -245,8 +243,6 @@ out:
 ''',
                  c_name=c_name(name))

-    return ret
-

 class QAPISchemaGenVisitVisitor(QAPISchemaVisitor):
     def __init__(self):
@@ -268,11 +264,6 @@ class QAPISchemaGenVisitVisitor(QAPISchemaVisitor):
         self.decl = self._btin + self.decl
         self._btin = None

-    def visit_needed(self, entity):
-        # Visit everything except implicit objects
-        return not (entity.is_implicit() and
-                    isinstance(entity, QAPISchemaObjectType))
-
     def visit_enum_type(self, name, info, values, prefix):
         # Special case for our lone builtin enum type
         # TODO use something cleaner than existence of info
@@ -296,9 +287,17 @@ class QAPISchemaGenVisitVisitor(QAPISchemaVisitor):
             self.defn += defn

     def visit_object_type(self, name, info, base, members, variants):
+        # Nothing to do for the special empty builtin
+        if name == 'q_empty':
+            return
         self.decl += gen_visit_members_decl(name)
-        self.decl += gen_visit_decl(name)
-        self.defn += gen_visit_object(name, base, members, variants)
+        self.defn += gen_visit_object_members(name, base, members, variants)
+        # TODO Worth changing the visitor signature, so we could
+        # directly use rather than repeat type.is_implicit()?
+        if not name.startswith('q_'):
+            # only explicit types need an allocating visit
+            self.decl += gen_visit_decl(name)
+            self.defn += gen_visit_object(name, base, members, variants)

     def visit_alternate_type(self, name, info, variants):
         self.decl += gen_visit_decl(name)
