diff --git a/src/include/units/concepts.h b/src/include/units/concepts.h
index a60a852c..27ec3a0b 100644
--- a/src/include/units/concepts.h
+++ b/src/include/units/concepts.h
@@ -27,6 +27,8 @@
 #include <units/bits/external/hacks.h>
 #include <units/ratio.h>
 #include <units/bits/external/type_traits.h>
+#include <cstdint>
+#include <utility>
 
 namespace units {