diff --git a/fs/mmap/fs_munmap.c b/fs/mmap/fs_munmap.c
index a4fa9b24c9..0ff1db4d64 100644
--- a/fs/mmap/fs_munmap.c
+++ b/fs/mmap/fs_munmap.c
@@ -198,6 +198,7 @@ int munmap(FAR void *start, size_t length)
     {
       newaddr = kumm_realloc(curr->addr, sizeof(struct fs_rammap_s) + length);
       DEBUGASSERT(newaddr == (FAR void *)(curr->addr));
+      UNUSED(newaddr); /* May not be used */
       curr->length = length;
     }