diff --git a/ChangeLog b/ChangeLog
index 393d47a7e7..d5bd5613a5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Sun Feb 19 23:43:38 2012  Tanaka Akira  <akr@fsij.org>
+
+	* ext/dbm/extconf.rb: show header and library found.
+
 Sun Feb 19 23:01:01 2012  Tanaka Akira  <akr@fsij.org>
 
 	* ext/dbm/dbm.c (Init_dbm): refine DBM::VERSION definition.
diff --git a/ext/dbm/extconf.rb b/ext/dbm/extconf.rb
index 26f799cc5b..72b8a1a70b 100644
--- a/ext/dbm/extconf.rb
+++ b/ext/dbm/extconf.rb
@@ -223,6 +223,9 @@ def headers.db_check2(db, hdr)
   $defs << '-DDBM_HDR="<'+hdr+'>"'
   @found << hdr
 
+  puts "header: #{hdr}"
+  puts "library: #{db}"
+
   true
 end