diff --git a/src/entt/meta/container.hpp b/src/entt/meta/container.hpp
index 4ca4cb022..8f0295e72 100644
--- a/src/entt/meta/container.hpp
+++ b/src/entt/meta/container.hpp
@@ -4,9 +4,9 @@
 #define ENTT_META_CONTAINER_HPP
 
 #include <array>
+#include <cstddef>
 #include <deque>
 #include <iterator>
-#include <limits>
 #include <list>
 #include <map>
 #include <set>
@@ -18,14 +18,12 @@
 #include "../container/dense_set.hpp"
 #include "../core/type_traits.hpp"
 #include "context.hpp"
+#include "fwd.hpp"
 #include "meta.hpp"
 #include "type_traits.hpp"
 
 namespace entt {
 
-/*! @brief Used to identicate that a sequence container has not a fixed size. */
-inline constexpr std::size_t meta_dynamic_extent = std::numeric_limits<std::size_t>::max();
-
 /*! @cond TURN_OFF_DOXYGEN */
 namespace internal {
 
diff --git a/src/entt/meta/fwd.hpp b/src/entt/meta/fwd.hpp
index 1114f480a..25097ccaf 100644
--- a/src/entt/meta/fwd.hpp
+++ b/src/entt/meta/fwd.hpp
@@ -1,6 +1,9 @@
 #ifndef ENTT_META_FWD_HPP
 #define ENTT_META_FWD_HPP
 
+#include <cstddef>
+#include <limits>
+
 namespace entt {
 
 class meta_ctx;
@@ -24,6 +27,9 @@ class meta_type;
 template<typename>
 class meta_factory;
 
+/*! @brief Used to identicate that a sequence container has not a fixed size. */
+inline constexpr std::size_t meta_dynamic_extent = std::numeric_limits<std::size_t>::max();
+
 } // namespace entt
 
 #endif