diff --git a/ares/nameser.h b/ares/nameser.h
index 6f68f41d00bb89104f29e770adb7a90f263fa700..73a9e18423461b2dc6f295d5f31f9104d47b8bbc 100644
--- a/ares/nameser.h
+++ b/ares/nameser.h
@@ -5,6 +5,7 @@
    port build */
 
 #include <windows.h>
+#include <process.h> /* for the _getpid() proto */
 #include <sys/types.h>
 
 #define MAXHOSTNAMELEN 256