diff --git a/process.c b/process.c
index 0b42cc9592..b7058b04c3 100644
--- a/process.c
+++ b/process.c
@@ -94,6 +94,11 @@ static VALUE S_Tms;
 #define HAVE_44BSD_SETGID 1
 #endif
 
+#ifdef __NetBSD__
+#undef HAVE_SETRUID
+#undef HAVE_SETRGID
+#endif
+
 #if defined(__MacOS_X__) || defined(__bsdi__)
 #define BROKEN_SETREUID 1
 #define BROKEN_SETREGID 1