diff --git a/src/include/espeak-ng/encoding.h b/src/include/espeak-ng/encoding.h
index 640782a6..9cc8a5d8 100644
--- a/src/include/espeak-ng/encoding.h
+++ b/src/include/espeak-ng/encoding.h
@@ -17,6 +17,8 @@
 #ifndef ESPEAK_NG_ENCODING_H
 #define ESPEAK_NG_ENCODING_H
 
+#include <stdint.h>
+
 #ifdef __cplusplus
 extern "C"
 {