diff --git a/include/woff2/output.h b/include/woff2/output.h
index dc78ccf..b12d538 100644
--- a/include/woff2/output.h
+++ b/include/woff2/output.h
@@ -9,6 +9,8 @@
 #ifndef WOFF2_WOFF2_OUT_H_
 #define WOFF2_WOFF2_OUT_H_
 
+#include <stdint.h>
+
 #include <algorithm>
 #include <cstring>
 #include <memory>