diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
index 2f4cef67cf64..e4e59a4e0d90 100644
--- a/fs/erofs/decompressor.c
+++ b/fs/erofs/decompressor.c
@@ -142,6 +142,7 @@ static void *z_erofs_lz4_handle_overlap(const struct z_erofs_decompress_req *rq,
 	oend = rq->pageofs_out + rq->outputsize;
 	omargin = PAGE_ALIGN(oend) - oend;
 	if (!rq->partial_decoding && may_inplace &&
+	    rq->outpages >= rq->inpages &&
 	    omargin >= LZ4_DECOMPRESS_INPLACE_MARGIN(rq->inputsize)) {
 		for (i = 0; i < rq->inpages; ++i)
 			if (rq->out[rq->outpages - rq->inpages + i] !=