diff --git a/src/liblzma/common/index.c b/src/liblzma/common/index.c
index c4aadb9b..4d641f9b 100644
--- a/src/liblzma/common/index.c
+++ b/src/liblzma/common/index.c
@@ -974,6 +974,7 @@ lzma_index_dup(const lzma_index *src, const lzma_allocator *allocator)
 	dest->total_size = src->total_size;
 	dest->record_count = src->record_count;
 	dest->index_list_size = src->index_list_size;
+	dest->checks = src->checks;
 
 	// Copy the Streams and the groups in them.
 	const index_stream *srcstream