diff --git a/config.hpp b/config.hpp
index 53d29cf..5d01254 100644
--- a/config.hpp
+++ b/config.hpp
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <stdint.h>
+
 namespace uart {
 
 enum class DataBits {
diff --git a/hardware.hpp b/hardware.hpp
index 1aec066..37100a0 100644
--- a/hardware.hpp
+++ b/hardware.hpp
@@ -1,5 +1,9 @@
 #pragma once
 
+#include "../clock.h"
+
+#include <stdint.h>
+
 #define FORCE_INLINE __attribute__((always_inline))
 
 namespace uart {
diff --git a/hardware0.hpp b/hardware0.hpp
index 0dc82e4..ace10ba 100644
--- a/hardware0.hpp
+++ b/hardware0.hpp
@@ -1,5 +1,9 @@
 #pragma once
 
+#include <stdint.h>
+
+#include <avr/io.h>
+
 #include "config.hpp"
 #include "hardware.hpp"
 
diff --git a/hardware1.hpp b/hardware1.hpp
index 51360e9..f3e8572 100644
--- a/hardware1.hpp
+++ b/hardware1.hpp
@@ -1,5 +1,9 @@
 #pragma once
 
+#include <stdint.h>
+
+#include <avr/io.h>
+
 #include "config.hpp"
 #include "hardware.hpp"