--- modules/clx/new-clx/clx.f
+++ modules/clx/new-clx/clx.f	2007-01-24 11:33:44.000000000 +0100
@@ -1563,7 +1563,8 @@ static void general_lookup (object type)
   DEFUN(XLIB:##L##-ID,xxx)                                              \
     { VALUES1(make_uint29((XID)get_##c (popSTACK()))); }                \
   DEFUN(XLIB:##L##-EQUAL,xxx yyy)                                       \
-    { VALUES_IF(get_##c (popSTACK()) == get_##c (popSTACK())); }        \
+    { object _last = popSTACK();                                        \
+      VALUES_IF(get_##c (popSTACK()) == get_##c (_last)); }             \
   DEFUN(XLIB:LOOKUP-##L,display xxx)                                    \
     { general_lookup (`XLIB::##L##`); }
 
@@ -1580,7 +1581,8 @@ static void general_lookup (object type)
   DEFUN(XLIB:##L##-P,xxx)                                               \
     { VALUES_IF(c##_p (popSTACK())); }                                  \
   DEFUN(XLIB:##L##-EQUAL,xxx yyy)                                       \
-    { VALUES_IF(get_##c (popSTACK()) == get_##c (popSTACK())); }
+    { object _last = popSTACK();                                        \
+      VALUES_IF(get_##c (popSTACK()) == get_##c (_last)); }
 
 
 /* -----------------------------------------------------------------------