diff --git a/adb/file_sync_protocol.h b/adb/file_sync_protocol.h
index 508c13851..87ede0c0c 100644
--- a/adb/file_sync_protocol.h
+++ b/adb/file_sync_protocol.h
@@ -41,57 +41,69 @@ struct SyncRequest {
     // Followed by 'path_length' bytes of path (not NUL-terminated).
 } __attribute__((packed));
 
+struct __attribute__((packed)) sync_stat_v1 {
+    uint32_t id;
+    uint32_t mode;
+    uint32_t size;
+    uint32_t mtime;
+};
+
+struct __attribute__((packed)) sync_stat_v2 {
+    uint32_t id;
+    uint32_t error;
+    uint64_t dev;
+    uint64_t ino;
+    uint32_t mode;
+    uint32_t nlink;
+    uint32_t uid;
+    uint32_t gid;
+    uint64_t size;
+    int64_t atime;
+    int64_t mtime;
+    int64_t ctime;
+};
+
+struct __attribute__((packed)) sync_dent_v1 {
+    uint32_t id;
+    uint32_t mode;
+    uint32_t size;
+    uint32_t mtime;
+    uint32_t namelen;
+};  // followed by `namelen` bytes of the name.
+
+struct __attribute__((packed)) sync_dent_v2 {
+    uint32_t id;
+    uint32_t error;
+    uint64_t dev;
+    uint64_t ino;
+    uint32_t mode;
+    uint32_t nlink;
+    uint32_t uid;
+    uint32_t gid;
+    uint64_t size;
+    int64_t atime;
+    int64_t mtime;
+    int64_t ctime;
+    uint32_t namelen;
+};  // followed by `namelen` bytes of the name.
+
+struct __attribute__((packed)) sync_data {
+    uint32_t id;
+    uint32_t size;
+};  // followed by `size` bytes of data.
+
+struct __attribute__((packed)) sync_status {
+    uint32_t id;
+    uint32_t msglen;
+};  // followed by `msglen` bytes of error message, if id == ID_FAIL.
+
 union syncmsg {
-    struct __attribute__((packed)) {
-        uint32_t id;
-        uint32_t mode;
-        uint32_t size;
-        uint32_t mtime;
-    } stat_v1;
-    struct __attribute__((packed)) {
-        uint32_t id;
-        uint32_t error;
-        uint64_t dev;
-        uint64_t ino;
-        uint32_t mode;
-        uint32_t nlink;
-        uint32_t uid;
-        uint32_t gid;
-        uint64_t size;
-        int64_t atime;
-        int64_t mtime;
-        int64_t ctime;
-    } stat_v2;
-    struct __attribute__((packed)) {
-        uint32_t id;
-        uint32_t mode;
-        uint32_t size;
-        uint32_t mtime;
-        uint32_t namelen;
-    } dent_v1; // followed by `namelen` bytes of the name.
-    struct __attribute__((packed)) {
-        uint32_t id;
-        uint32_t error;
-        uint64_t dev;
-        uint64_t ino;
-        uint32_t mode;
-        uint32_t nlink;
-        uint32_t uid;
-        uint32_t gid;
-        uint64_t size;
-        int64_t atime;
-        int64_t mtime;
-        int64_t ctime;
-        uint32_t namelen;
-    } dent_v2; // followed by `namelen` bytes of the name.
-    struct __attribute__((packed)) {
-        uint32_t id;
-        uint32_t size;
-    } data; // followed by `size` bytes of data.
-    struct __attribute__((packed)) {
-        uint32_t id;
-        uint32_t msglen;
-    } status; // followed by `msglen` bytes of error message, if id == ID_FAIL.
+    sync_stat_v1 stat_v1;
+    sync_stat_v2 stat_v2;
+    sync_dent_v1 dent_v1;
+    sync_dent_v2 dent_v2;
+    sync_data data;
+    sync_status status;
 };
 
 #define SYNC_DATA_MAX (64 * 1024)