diff --git a/debug/known_sizes.c b/debug/known_sizes.c
index cdee26df..6c3641f8 100644
--- a/debug/known_sizes.c
+++ b/debug/known_sizes.c
@@ -87,7 +87,7 @@ main(void)
 			!= LZMA_OK)
 		return 1;
 
-	lzma_index *idx = lzma_index_init(NULL, NULL);
+	lzma_index *idx = lzma_index_init(NULL);
 	if (idx == NULL)
 		return 1;