diff --git a/fs/mmap/fs_mmap.c b/fs/mmap/fs_mmap.c
index 6a471a723a8..d58ea4cfdb2 100644
--- a/fs/mmap/fs_mmap.c
+++ b/fs/mmap/fs_mmap.c
@@ -68,6 +68,7 @@ static int file_mmap_(FAR struct file *filep, FAR void *start,
      prot,
      flags,
      { NULL }, /* priv.p */
+     NULL,     /* msync */
      NULL      /* munmap */
     };