diff --git a/src/core/piincludes_p.h b/src/core/piincludes_p.h
index e95f240a..11e710ae 100644
--- a/src/core/piincludes_p.h
+++ b/src/core/piincludes_p.h
@@ -31,6 +31,7 @@ typedef void(*PINtSetTimerResolution)(ULONG, BOOLEAN, PULONG);
 #endif
 #include <string>
 #include <iostream>
+#include <stdlib.h>
 
 
 #endif // PIINCLUDES_P_H