diff --git a/flat_map.hpp b/flat_map.hpp
index c5a5e94..2116937 100644
--- a/flat_map.hpp
+++ b/flat_map.hpp
@@ -388,7 +388,7 @@ namespace flat_hpp
         const flat_map<Key, Value, Compare, Allocator, Container>& r)
     {
         return l.size() == r.size()
-            && std::equal(l.begin(), l.end(), r.begin(), r.end());
+            && std::equal(l.begin(), l.end(), r.begin());
     }
 
     template < typename Key
diff --git a/flat_set.hpp b/flat_set.hpp
index c908d1f..da77c6f 100644
--- a/flat_set.hpp
+++ b/flat_set.hpp
@@ -334,7 +334,7 @@ namespace flat_hpp
         const flat_set<Key, Compare, Allocator, Container>& r)
     {
         return l.size() == r.size()
-            && std::equal(l.begin(), l.end(), r.begin(), r.end());
+            && std::equal(l.begin(), l.end(), r.begin());
     }
 
     template < typename Key