diff --git a/ConflictSet.cpp b/ConflictSet.cpp
index 3756d37..d6ea2f9 100644
--- a/ConflictSet.cpp
+++ b/ConflictSet.cpp
@@ -1606,6 +1606,7 @@ void rezero(Node *n, InternalVersionT z) {
 
 void mergeWithChild(Node *&self, WriteContext *tls, ConflictSet::Impl *impl,
                     Node *&dontInvalidate, Node3 *self3) {
+  assert(!self3->entryPresent);
   auto *child = self3->children[0];
   int minCapacity = self3->partialKeyLen + 1 + child->partialKeyLen;
 
@@ -1639,7 +1640,7 @@ void mergeWithChild(Node *&self, WriteContext *tls, ConflictSet::Impl *impl,
   // that we have a new parent.
   setMaxVersion(child, impl, std::max(childMaxVersion, tls->zero));
 
-  getInTree(self, impl) = child;
+  self = child;
   tls->release(self3);
 }
 
@@ -1662,7 +1663,7 @@ void maybeDownsize(Node *self, WriteContext *tls, ConflictSet::Impl *impl,
       getInTree(self, impl) = newSelf;
       tls->release(self3);
     } else if (self->numChildren == 1 && !self->entryPresent) {
-      mergeWithChild(self, tls, impl, dontInvalidate, self3);
+      mergeWithChild(getInTree(self, impl), tls, impl, dontInvalidate, self3);
     }
   } break;
   case Type_Node16: