--- Compress-LZF/LZF.xs	2001/09/27 19:24:55	1.2
+++ Compress-LZF/LZF.xs	2001/09/27 19:51:26	1.3
@@ -225,7 +225,9 @@
         PROTOTYPE: $
         PPCODE:
 
-        if (SvROK (sv)) /* mstore */
+        if (SvTYPE(sv) != SVt_IV
+            && SvTYPE(sv) != SVt_NV
+            && SvTYPE(sv) != SVt_PV) /* mstore */
           {
             if (!storable_mstore)
               need_storable ();