diff --git a/include/yaml-cpp/node/detail/iterator.h b/include/yaml-cpp/node/detail/iterator.h
index cc5f9d3..65f8152 100644
--- a/include/yaml-cpp/node/detail/iterator.h
+++ b/include/yaml-cpp/node/detail/iterator.h
@@ -61,12 +61,12 @@ class iterator_base : public std::iterator<std::forward_iterator_tag, V,
   }
 
   template <typename W>
-  bool operator==(const iterator_base<W>& rhs) {
+  bool operator==(const iterator_base<W>& rhs) const {
     return m_iterator == rhs.m_iterator;
   }
 
   template <typename W>
-  bool operator!=(const iterator_base<W>& rhs) {
+  bool operator!=(const iterator_base<W>& rhs) const {
     return m_iterator != rhs.m_iterator;
   }