diff --git a/scripts/qapi.py b/scripts/qapi.py
index 00a16203df..7c50cc4c87 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -490,7 +490,7 @@ def check_type(expr_info, source, value, allow_array=False,
     for (key, arg) in value.items():
         check_name(expr_info, "Member of %s" % source, key,
                    allow_optional=allow_optional)
-        if c_name(key, False).startswith('has_'):
+        if c_name(key, False) == 'u' or c_name(key, False).startswith('has_'):
             raise QAPIExprError(expr_info,
                                 "Member of %s uses reserved name '%s'"
                                 % (source, key))
diff --git a/tests/Makefile b/tests/Makefile
index fd4ec03e09..92969e8288 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -318,6 +318,7 @@ qapi-schema += redefined-type.json
 qapi-schema += reserved-command-q.json
 qapi-schema += reserved-member-has.json
 qapi-schema += reserved-member-q.json
+qapi-schema += reserved-member-u.json
 qapi-schema += reserved-type-kind.json
 qapi-schema += reserved-type-list.json
 qapi-schema += returns-alternate.json
diff --git a/tests/qapi-schema/reserved-member-u.err b/tests/qapi-schema/reserved-member-u.err
new file mode 100644
index 0000000000..87d42296cc
--- /dev/null
+++ b/tests/qapi-schema/reserved-member-u.err
@@ -0,0 +1 @@
+tests/qapi-schema/reserved-member-u.json:7: Member of 'data' for struct 'Oops' uses reserved name 'u'
diff --git a/tests/qapi-schema/reserved-member-u.exit b/tests/qapi-schema/reserved-member-u.exit
new file mode 100644
index 0000000000..d00491fd7e
--- /dev/null
+++ b/tests/qapi-schema/reserved-member-u.exit
@@ -0,0 +1 @@
+1
diff --git a/tests/qapi-schema/reserved-member-u.json b/tests/qapi-schema/reserved-member-u.json
new file mode 100644
index 0000000000..1eaf0f301c
--- /dev/null
+++ b/tests/qapi-schema/reserved-member-u.json
@@ -0,0 +1,7 @@
+# Potential C member name collision
+# We reject use of 'u' as a member name, to allow it for internal use in
+# putting union branch members in a separate namespace from QMP members.
+# This is true even for non-unions, because it is possible to convert a
+# struct to flat union while remaining backwards compatible in QMP.
+# TODO - we could munge the member name to 'q_u' to avoid the collision
+{ 'struct': 'Oops', 'data': { 'u': 'str' } }
diff --git a/tests/qapi-schema/reserved-member-u.out b/tests/qapi-schema/reserved-member-u.out
new file mode 100644
index 0000000000..e69de29bb2