diff --git a/cf/roken-frag.m4 b/cf/roken-frag.m4
index 11dcb85d6..ee2ffdf1d 100644
--- a/cf/roken-frag.m4
+++ b/cf/roken-frag.m4
@@ -162,6 +162,7 @@ AC_CHECK_FUNCS([				\
 	getrlimit				\
 	getspnam				\
 	initstate				\
+	issetugid				\
 	random					\
 	setprogname				\
 	setstate				\