diff --git a/vlib-api/vlibmemory/api.h b/vlib-api/vlibmemory/api.h
index 117bf43..516d321 100644
--- a/vlib-api/vlibmemory/api.h
+++ b/vlib-api/vlibmemory/api.h
@@ -86,6 +86,13 @@
 
 } vl_shmem_hdr_t;
 
+/* Note that the size of the structure is 16 bytes, with 4 bytes of padding after data[0]. */
+typedef struct msgbuf_ {
+    unix_shared_memory_queue_t *q;
+    u32 data_len;
+    u8 data[0];
+} msgbuf_t;
+
 #define VL_SHM_VERSION 2
 
 #define VL_API_EPOCH_MASK 0xFF