diff --git a/ChangeLog b/ChangeLog
index 4605df1c1a..f78b4c0445 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Sun Aug 24 12:02:39 2008  Tanaka Akira  <akr@fsij.org>
+
+	* transcode.c (rb_econv_open): return NULL on error.
+
 Sun Aug 24 11:40:38 2008  Tanaka Akira  <akr@fsij.org>
 
 	* include/ruby/encoding.h (rb_econv_open_exc): declared.
diff --git a/transcode.c b/transcode.c
index ce3455df0f..5e14a358b8 100644
--- a/transcode.c
+++ b/transcode.c
@@ -780,7 +780,7 @@ rb_econv_open(const char *from, const char *to, int flags)
     ec = rb_econv_open_by_transcoder_entries(num_trans, entries);
     xfree(entries);
     if (!ec)
-        rb_raise(rb_eArgError, "encoding conversion not supported (from %s to %s)", from, to);
+        return NULL;
 
     ec->flags = flags;
     ec->source_encoding_name = from;