diff --git a/scripts/qapi-commands.py b/scripts/qapi-commands.py
index b12b6964ef..b9c41fb605 100644
--- a/scripts/qapi-commands.py
+++ b/scripts/qapi-commands.py
@@ -119,7 +119,7 @@ bool has_%(argname)s = false;
                          argname=c_var(argname), argtype=c_type(argtype))
         else:
             ret += mcgen('''
-%(argtype)s %(argname)s;
+%(argtype)s %(argname)s = {0};
 ''',
                          argname=c_var(argname), argtype=c_type(argtype))