diff --git a/lfs.c b/lfs.c
index 4c914ee..31297c1 100644
--- a/lfs.c
+++ b/lfs.c
@@ -3095,8 +3095,8 @@ static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
     lfs_cache_zero(lfs, &lfs->rcache);
     lfs_cache_zero(lfs, &lfs->pcache);
 
-    // setup lookahead, must be multiple of 32-bits
-    LFS_ASSERT(lfs->cfg->lookahead_size % 4 == 0);
+    // setup lookahead, must be multiple of 64-bits
+    LFS_ASSERT(lfs->cfg->lookahead_size % 8 == 0);
     LFS_ASSERT(lfs->cfg->lookahead_size > 0);
     if (lfs->cfg->lookahead_buffer) {
         lfs->free.buffer = lfs->cfg->lookahead_buffer;