diff --git a/ChangeLog b/ChangeLog
index d2c775f3de..039141206f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,9 @@
-Tue Jun 13 17:06:20 2008  wanabe  <s.wanabe@gmail.com>
+Fri Jun 13 17:20:40 2008  wanabe  <s.wanabe@gmail.com>
+
+	* complex.c (string_to_c_internal): save and restore backref.
+	  fixed [ruby-dev:34991]
+
+Fri Jun 13 17:06:20 2008  wanabe  <s.wanabe@gmail.com>
 
 	* rational.c (string_to_r_internal): save and restore backref.
 	  fixed [ruby-dev:34990]
diff --git a/complex.c b/complex.c
index 1485d13484..935d4d6f2b 100644
--- a/complex.c
+++ b/complex.c
@@ -1153,8 +1153,10 @@ string_to_c_internal(VALUE self)
 	return rb_assoc_new(Qnil, self);
 
     {
-	VALUE m, sr, si, re, r, i;
+	VALUE m, sr, si, re, r, i, backref;
 
+	backref = rb_backref_get();
+	rb_match_busy(backref);
 	m = f_match(comp_pat1, s);
 	if (!NIL_P(m)) {
 	    sr = Qnil;
@@ -1170,8 +1172,10 @@ string_to_c_internal(VALUE self)
 	}
 	if (NIL_P(m)) {
 	    m = f_match(comp_pat2, s);
-	    if (NIL_P(m))
+	    if (NIL_P(m)) {
+		rb_backref_set(backref);
 		return rb_assoc_new(Qnil, self);
+	    }
 	    sr = f_aref(m, INT2FIX(1));
 	    if (NIL_P(f_aref(m, INT2FIX(2))))
 		si = Qnil;
@@ -1206,6 +1210,7 @@ string_to_c_internal(VALUE self)
 	    else
 		i = f_to_i(si);
 	}
+	rb_backref_set(backref);
 	return rb_assoc_new(rb_complex_new2(r, i), re);
     }
 }