diff --git a/libtree/src/red_black_tree.rs b/libtree/src/red_black_tree.rs
index f0f0f22..7a690c9 100644
--- a/libtree/src/red_black_tree.rs
+++ b/libtree/src/red_black_tree.rs
@@ -293,7 +293,7 @@ impl RedBlackTree {
                 if !uncle.is_null() && uncle.colour() == Red {
                     uncle.set_colour(Black);
                     parent.set_colour(Black);
-                    grandparent.set_colour(Black);
+                    grandparent.set_colour(Red);
                     node = grandparent;
                 } else {
                     if parent.left() == node {