diff --git a/src/EC/Bitset.hpp b/src/EC/Bitset.hpp
index 8db60b7..b6faf73 100644
--- a/src/EC/Bitset.hpp
+++ b/src/EC/Bitset.hpp
@@ -11,6 +11,7 @@
 #include "Meta/Combine.hpp"
 #include "Meta/IndexOf.hpp"
 #include "Meta/ForEach.hpp"
+#include "Meta/Contains.hpp"
 
 namespace EC
 {
diff --git a/src/EC/Manager.hpp b/src/EC/Manager.hpp
index 27204cd..38fb167 100644
--- a/src/EC/Manager.hpp
+++ b/src/EC/Manager.hpp
@@ -14,6 +14,7 @@
 #include <utility>
 
 #include "Meta/Combine.hpp"
+#include "Meta/Matching.hpp"
 #include "Bitset.hpp"
 
 namespace EC