diff --git a/ChangeLog b/ChangeLog
index 978ecfc5e7..0c6c940f91 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu May  8 10:53:14 2014  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* configure.in: OpenBSD needs to include sys/param.h before include
+	  sys/mount.h. [ruby-dev:48167]
+
 Thu May  8 10:17:04 2014  Karsten Sperling  <karsten@sperling.co.nz>
 
 	* lib/webrick/httpserver.rb (WEBrick::HTTPServer#run): stop
diff --git a/configure.in b/configure.in
index 57bb40086a..e50e717d46 100644
--- a/configure.in
+++ b/configure.in
@@ -1121,7 +1121,6 @@ AC_CHECK_HEADERS( \
   sys/syscall.h \
   fcntl.h \
   sys/fcntl.h \
-  sys/mount.h \
   sys/select.h \
   sys/time.h \
   sys/times.h \
@@ -1155,6 +1154,9 @@ AC_CHECK_HEADERS( \
   malloc/malloc.h \
   setjmpex.h
 )
+AC_CHECK_HEADERS(sys/mount.h, [], [], [@%:@ifdef HAVE_SYS_PARAM_H
+@%:@ include <sys/param.h>
+@%:@endif])
 
 AC_ARG_WITH([gmp],
   [AS_HELP_STRING([--without-gmp],