diff --git a/cf/roken-frag.m4 b/cf/roken-frag.m4
index 73ba26fb5..86db02ee8 100644
--- a/cf/roken-frag.m4
+++ b/cf/roken-frag.m4
@@ -69,6 +69,7 @@ AC_CHECK_HEADERS([\
 	shadow.h				\
 	sys/bswap.h				\
 	sys/ioctl.h				\
+	sys/mman.h				\
 	sys/param.h				\
 	sys/proc.h				\
 	sys/resource.h				\
@@ -205,6 +206,8 @@ fi
 
 AC_REQUIRE([AC_FUNC_GETLOGIN])
 
+AC_REQUIRE([AC_FUNC_MMAP])
+
 AC_FIND_FUNC_NO_LIBS(getsockopt,,
 [#ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>