diff --git a/qt/formatter.h b/qt/formatter.h
index e667c0861..6b8c11906 100644
--- a/qt/formatter.h
+++ b/qt/formatter.h
@@ -13,6 +13,8 @@
 #ifndef QTR_UNITS
 #define QTR_UNITS
 
+#include <inttypes.h> /* uint64_t */
+
 #include <QString>
 #include <QObject>
 #include <QIcon>