=== modified file 'src/lread.c'
--- src/lread.c	2010-06-16 14:10:02 +0000
+++ src/lread.c	2010-06-22 07:48:58 +0000
@@ -2693,21 +2693,26 @@
 	 old-style.  For Emacs-25, we should completely remove this
 	 first_in_list exception (old-style can still be obtained via
 	 "(\`" anyway).  */
-      if (first_in_list && (c = READCHAR, UNREAD (c), c == ' '))
-	{
-	  Vold_style_backquotes = Qt;
-	  goto default_label;
-	}
-      else
-	{
-	  Lisp_Object value;
-
-	  new_backquote_flag++;
-	  value = read0 (readcharfun);
-	  new_backquote_flag--;
-
-	  return Fcons (Qbackquote, Fcons (value, Qnil));
-	}
+      {
+        int next_char = READCHAR;
+        UNREAD (next_char);
+
+	if (first_in_list && next_char == ' ')
+	  {
+	    Vold_style_backquotes = Qt;
+	    goto default_label;
+	  }
+	else
+	  {
+	    Lisp_Object value;
+
+	    new_backquote_flag++;
+	    value = read0 (readcharfun);
+	    new_backquote_flag--;
+
+	    return Fcons (Qbackquote, Fcons (value, Qnil));
+	  }
+      }
 
     case ',':
       if (new_backquote_flag)