diff --git a/block/block-gen.h b/block/block-gen.h
index f80cf4897d..8ac9d5bd4f 100644
--- a/block/block-gen.h
+++ b/block/block-gen.h
@@ -32,18 +32,15 @@
 typedef struct BdrvPollCo {
     BlockDriverState *bs;
     bool in_progress;
-    int ret;
     Coroutine *co; /* Keep pointer here for debugging */
 } BdrvPollCo;
 
-static inline int bdrv_poll_co(BdrvPollCo *s)
+static inline void bdrv_poll_co(BdrvPollCo *s)
 {
     assert(!qemu_in_coroutine());
 
     bdrv_coroutine_enter(s->bs, s->co);
     BDRV_POLL_WHILE(s->bs, s->in_progress);
-
-    return s->ret;
 }
 
 #endif /* BLOCK_BLOCK_GEN_H */
diff --git a/scripts/block-coroutine-wrapper.py b/scripts/block-coroutine-wrapper.py
index 08be813407..dfad3a44f0 100644
--- a/scripts/block-coroutine-wrapper.py
+++ b/scripts/block-coroutine-wrapper.py
@@ -75,14 +75,15 @@ class FuncDecl:
 
 
 # Match wrappers declared with a generated_co_wrapper mark
-func_decl_re = re.compile(r'^int\s*generated_co_wrapper\s*'
+func_decl_re = re.compile(r'^(?P<return_type>[a-zA-Z][a-zA-Z0-9_]* [\*]?)'
+                          r'\s*generated_co_wrapper\s*'
                           r'(?P<wrapper_name>[a-z][a-z0-9_]*)'
                           r'\((?P<args>[^)]*)\);$', re.MULTILINE)
 
 
 def func_decl_iter(text: str) -> Iterator:
     for m in func_decl_re.finditer(text):
-        yield FuncDecl(return_type='int',
+        yield FuncDecl(return_type=m.group('return_type'),
                        name=m.group('wrapper_name'),
                        args=m.group('args'))
 
@@ -99,7 +100,6 @@ def snake_to_camel(func_name: str) -> str:
 
 def gen_wrapper(func: FuncDecl) -> str:
     assert not '_co_' in func.name
-    assert func.return_type == 'int'
     assert func.args[0].type in ['BlockDriverState *', 'BdrvChild *',
                                  'BlockBackend *']
 
@@ -123,6 +123,7 @@ def gen_wrapper(func: FuncDecl) -> str:
 
 typedef struct {struct_name} {{
     BdrvPollCo poll_state;
+    {func.return_type} ret;
 { func.gen_block('    {decl};') }
 }} {struct_name};
 
@@ -130,13 +131,13 @@ static void coroutine_fn {name}_entry(void *opaque)
 {{
     {struct_name} *s = opaque;
 
-    s->poll_state.ret = {name}({ func.gen_list('s->{name}') });
+    s->ret = {name}({ func.gen_list('s->{name}') });
     s->poll_state.in_progress = false;
 
     aio_wait_kick();
 }}
 
-int {func.name}({ func.gen_list('{decl}') })
+{func.return_type} {func.name}({ func.gen_list('{decl}') })
 {{
     if (qemu_in_coroutine()) {{
         return {name}({ func.gen_list('{name}') });
@@ -150,7 +151,8 @@ int {func.name}({ func.gen_list('{decl}') })
 
         s.poll_state.co = qemu_coroutine_create({name}_entry, &s);
 
-        return bdrv_poll_co(&s.poll_state);
+        bdrv_poll_co(&s.poll_state);
+        return s.ret;
     }}
 }}"""