diff --git a/headers/flat_hpp/flat_map.hpp b/headers/flat_hpp/flat_map.hpp
index 90306f9..f914b62 100644
--- a/headers/flat_hpp/flat_map.hpp
+++ b/headers/flat_hpp/flat_map.hpp
@@ -87,7 +87,7 @@ namespace flat_hpp
             std::is_same<typename container_type::allocator_type, allocator_type>::value,
             "Container::allocator_type must be same type as allocator_type");
     public:
-        flat_map() = default;
+        flat_map() {}
 
         explicit flat_map(
             const Allocator& a)
diff --git a/headers/flat_hpp/flat_set.hpp b/headers/flat_hpp/flat_set.hpp
index 7b0dd73..95ab531 100644
--- a/headers/flat_hpp/flat_set.hpp
+++ b/headers/flat_hpp/flat_set.hpp
@@ -56,7 +56,7 @@ namespace flat_hpp
             std::is_same<typename container_type::allocator_type, allocator_type>::value,
             "Container::allocator_type must be same type as allocator_type");
     public:
-        flat_set() = default;
+        flat_set() {}
 
         explicit flat_set(
             const Allocator& a)