diff --git a/src/entt/graph/adjacency_matrix.hpp b/src/entt/graph/adjacency_matrix.hpp
index 8fc0a5a62..65efc7d37 100644
--- a/src/entt/graph/adjacency_matrix.hpp
+++ b/src/entt/graph/adjacency_matrix.hpp
@@ -30,6 +30,7 @@ public:
     using reference = value_type;
     using difference_type = std::ptrdiff_t;
     using iterator_category = std::input_iterator_tag;
+    using iterator_concept = std::forward_iterator_tag;
 
     constexpr edge_iterator() noexcept
         : it{},