diff --git a/ChangeLog b/ChangeLog
index d95d619ab4..5cd3510696 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Sat Nov 12 17:01:49 2011  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* ext/dbm/extconf.rb (headers.db_check): reduce duplicated code.
+
 Sat Nov 12 15:59:42 2011  Tanaka Akira  <akr@fsij.org>
 
 	* ext/dbm/extconf.rb: dbm_clearerr should be available in all ndbm
diff --git a/ext/dbm/extconf.rb b/ext/dbm/extconf.rb
index 2fc5c441a5..b46688aa75 100644
--- a/ext/dbm/extconf.rb
+++ b/ext/dbm/extconf.rb
@@ -39,8 +39,8 @@ def headers.db_check(db)
     have_library("gdbm") or return false
   end
 
-  if (hdr = self.fetch(db, ["ndbm.h"]).find {|h| have_type("DBM", h, hsearch)} or
-      hdr = self.fetch(db, ["ndbm.h"]).find {|h| have_type("DBM", ["db.h", h], hsearch)}) and
+  hdrs = self.fetch(db, ["ndbm.h"])
+  if (hdr = hdrs.find {|h| have_type("DBM", h, hsearch)} || hdrs.find {|h| have_type("DBM", ["db.h", h], hsearch)}) and
      (have_library(db, 'dbm_open("", 0, 0)', hdr, hsearch) || have_func('dbm_open("", 0, 0)', hdr, hsearch)) and
      have_func('dbm_clearerr((DBM *)0)', hdr, hsearch)
     if hsearch