diff --git a/polymer/eduke32/build/src/kplib.c b/polymer/eduke32/build/src/kplib.c
index 381224eb3..e96e4b6c8 100644
--- a/polymer/eduke32/build/src/kplib.c
+++ b/polymer/eduke32/build/src/kplib.c
@@ -70,6 +70,7 @@ static __inline int32_t _lrotl(int32_t i, int sh)
 #define _fileno fileno
 #else
 #include <io.h>
+#include <intrin.h>
 #endif
 
 #if defined(_WIN32)