diff --git a/src/tokens.h b/src/tokens.h
index aa49761..8c69127 100644
--- a/src/tokens.h
+++ b/src/tokens.h
@@ -19,6 +19,7 @@
 #define _TOKENS_H_
 
 #include <stdint.h>
+#include "ethUstream.h"
 
 #define MAX_TICKER_LEN 12  // 10 characters + ' ' + '\0'