diff --git a/ChangeLog b/ChangeLog
index f540b445ff..a9f9272392 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Jul 21 04:42:15 2008  Tanaka Akira  <akr@fsij.org>
+
+	* re.c (rb_reg_s_union): useless rb_enc_get call removed to prevent
+	  SEGV by Regexp.union("", nil).
+
 Sun Jul 20 22:50:11 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* compile.c (iseq_compile_each): NODE_POSTEXE should set each end
diff --git a/re.c b/re.c
index 2bbf915e97..c061ef9e2f 100644
--- a/re.c
+++ b/re.c
@@ -3018,7 +3018,7 @@ rb_reg_s_union(VALUE self, VALUE args0)
 		v = rb_reg_to_s(v);
 	    }
 	    else {
-                rb_encoding *enc = rb_enc_get(e);
+                rb_encoding *enc;
                 StringValue(e);
                 enc = rb_enc_get(e);
                 if (!rb_enc_str_asciicompat_p(e)) {