--- a/btree_cache.c
+++ b/btree_cache.c
@@ -268,7 +268,7 @@
 static struct bt *get_disbalanced_node(struct bt *node)
 {
 	struct bt *rdn;
-	if (fabs(node->balanceinfo) > 1)
+	if (abs(node->balanceinfo) > 1)
 		return node;
 	if (node->left)
 	{