diff --git a/src/rbtree.cpp b/src/rbtree.cpp
index f01e31db51de94..a22133e54f23ab 100644
--- a/src/rbtree.cpp
+++ b/src/rbtree.cpp
@@ -70,10 +70,10 @@ class Tree
 
     template <int I>
     void fix_insert(Node* z) {
-        while (z != m_roots[I] && !z->m_positions[I].m_black) {
+        while (z != m_roots[I] && !z->m_positions[I].m_parent->m_positions[I].m_black) {
             if (z->m_positions[I].m_parent == z->m_positions[I].m_parent->m_positions[I].m_parent->m_positions[I].m_left) {
                 Node* y = z->m_positions[I].m_parent->m_positions[I].m_parent->m_positions[I].m_right;
-                if (y != nullptr && !z->m_positions[I].m_black) {
+                if (y != nullptr && !y->m_positions[I].m_black) {
                     z->m_positions[I].m_parent->m_positions[I].m_black = true;
                     y->m_positions[I].m_black = true;
                     z->m_positions[I].m_parent->m_positions[I].m_parent->m_positions[I].m_black = false;