diff --git a/ChangeLog b/ChangeLog
index 4382ebb60e..30aad5cbb6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Fri Oct 20 10:47:43 2006  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* lib/mkmf.rb: fixed the bug of handling COMMON_MACROS.
+
 Fri Oct 20 08:42:38 2006  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* common.mk (NULLCMD): dummy command.
diff --git a/lib/mkmf.rb b/lib/mkmf.rb
index 45900fe0f7..d24a407f9f 100644
--- a/lib/mkmf.rb
+++ b/lib/mkmf.rb
@@ -1511,8 +1511,7 @@ EXPORT_PREFIX = config_string('EXPORT_PREFIX') {|s| s.strip}
 hdr = []
 config_string('COMMON_MACROS') do |s|
   Shellwords.shellwords(s).each do |w|
-    /(.*?)(?:=(.*))/ =~ w
-    hdr << "#define #$1 #$2"
+    hdr << "#define " + w.split(/=/, 2).join(" ")
   end
 end
 config_string('COMMON_HEADERS') do |s|