diff --git a/block/vmdk.c b/block/vmdk.c
index bac3d8db50a5..8204eb9ff466 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -2285,10 +2285,11 @@ static int vmdk_init_extent(BlockBackend *blk,
     return ret;
 }
 
-static int vmdk_create_extent(const char *filename, int64_t filesize,
-                              bool flat, bool compress, bool zeroed_grain,
-                              BlockBackend **pbb,
-                              QemuOpts *opts, Error **errp)
+static int coroutine_fn vmdk_create_extent(const char *filename,
+                                           int64_t filesize, bool flat,
+                                           bool compress, bool zeroed_grain,
+                                           BlockBackend **pbb,
+                                           QemuOpts *opts, Error **errp)
 {
     int ret;
     BlockBackend *blk = NULL;
@@ -2366,14 +2367,14 @@ static int filename_decompose(const char *filename, char *path, char *prefix,
  *           non-split format.
  * idx >= 1: get the n-th extent if in a split subformat
  */
-typedef BlockBackend *(*vmdk_create_extent_fn)(int64_t size,
-                                               int idx,
-                                               bool flat,
-                                               bool split,
-                                               bool compress,
-                                               bool zeroed_grain,
-                                               void *opaque,
-                                               Error **errp);
+typedef BlockBackend * coroutine_fn (*vmdk_create_extent_fn)(int64_t size,
+                                                             int idx,
+                                                             bool flat,
+                                                             bool split,
+                                                             bool compress,
+                                                             bool zeroed_grain,
+                                                             void *opaque,
+                                                             Error **errp);
 
 static void vmdk_desc_add_extent(GString *desc,
                                  const char *extent_line_fmt,
@@ -2616,7 +2617,7 @@ typedef struct {
     QemuOpts *opts;
 } VMDKCreateOptsData;
 
-static BlockBackend *vmdk_co_create_opts_cb(int64_t size, int idx,
+static BlockBackend * coroutine_fn vmdk_co_create_opts_cb(int64_t size, int idx,
                                             bool flat, bool split, bool compress,
                                             bool zeroed_grain, void *opaque,
                                             Error **errp)
@@ -2768,10 +2769,11 @@ static int coroutine_fn vmdk_co_create_opts(BlockDriver *drv,
     return ret;
 }
 
-static BlockBackend *vmdk_co_create_cb(int64_t size, int idx,
-                                       bool flat, bool split, bool compress,
-                                       bool zeroed_grain, void *opaque,
-                                       Error **errp)
+static BlockBackend * coroutine_fn vmdk_co_create_cb(int64_t size, int idx,
+                                                     bool flat, bool split,
+                                                     bool compress,
+                                                     bool zeroed_grain,
+                                                     void *opaque, Error **errp)
 {
     int ret;
     BlockDriverState *bs;