diff --git a/inst/include/dotCall64.h b/inst/include/dotCall64.h
index c26bebd13b6adf7d6f82f64d864e00636a4e6df1..d06e6e35d3ebe2e11015487f4a577fa103278038 100644
--- a/inst/include/dotCall64.h
+++ b/inst/include/dotCall64.h
@@ -10,6 +10,8 @@
 // Defines INTSXP and REALSXP to be used in the args_type array.
 #include<Rinternals.h>
 
+// Defines int64_t on windows
+#include <stdint.h>
 
 /*
  * Because R does not define an int64 type, this pseudo type should be used to