diff --git a/poincare/include/poincare/opposite.h b/poincare/include/poincare/opposite.h
index e7f05c152..c5ca80ab5 100644
--- a/poincare/include/poincare/opposite.h
+++ b/poincare/include/poincare/opposite.h
@@ -18,7 +18,7 @@ public:
 
   // TreeNode
   size_t size() const override { return sizeof(OppositeNode); }
-  int numberOfChildren() const override { return 0; }
+  int numberOfChildren() const override { return 1; }
 #if POINCARE_TREE_LOG
   virtual void logNodeName(std::ostream & stream) const override {
     stream << "Opposite";