diff --git a/ChangeLog b/ChangeLog
index 6ce7709d47..bb0eb377cf 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sun Dec 28 21:09:12 2008  Yuki Sonoda (Yugui)  <yugui@yugui.jp>
+
+	* ext/dl/lib/dl/import.rb (DL::Importer#sizeof): follows
+	  a feature change in 1.9.
+
 Sun Dec 28 21:03:07 2008  Yuki Sonoda (Yugui)  <yugui@yugui.jp>
 
 	* ext/dl/lib/dl/import.rb (DL::Importer#extern): adds filename and
diff --git a/ext/dl/lib/dl/import.rb b/ext/dl/lib/dl/import.rb
index aab0a38d52..199354c18e 100644
--- a/ext/dl/lib/dl/import.rb
+++ b/ext/dl/lib/dl/import.rb
@@ -87,7 +87,7 @@ module DL
           raise(DLError, "unknown type: #{ty}")
         end
       when Class
-        if( ty.instance_methods().include?("to_ptr") )
+        if( ty.instance_methods().include?(:to_ptr) )
           return ty.size()
         end
       end