diff --git a/src/libsodium/crypto_stream/chacha20/ref/stream_chacha20_ref.h b/src/libsodium/crypto_stream/chacha20/ref/stream_chacha20_ref.h
index bfd6b500..f2091ab0 100644
--- a/src/libsodium/crypto_stream/chacha20/ref/stream_chacha20_ref.h
+++ b/src/libsodium/crypto_stream/chacha20/ref/stream_chacha20_ref.h
@@ -1,4 +1,6 @@
 
+#include <stdint.h>
+
 #include "crypto_stream_chacha20.h"
 
 extern struct crypto_stream_chacha20_implementation