diff --git a/Clone.xs b/Clone.xs
index dccdce5..5eeac07 100644
--- a/Clone.xs
+++ b/Clone.xs
@@ -174,7 +174,7 @@ sv_clone (SV * ref, HV* hseen, int depth)
 * Note: when using a Debug Perl with READONLY_COW
 * we cannot do 'sv_buf_to_rw + sv_buf_to_ro' as these APIs calls are not exported
 */
-#if PERL_VERSION >= 20 && !defined(PERL_DEBUG_READONLY_COW)
+#if defined(SV_COW_REFCNT_MAX) && !defined(PERL_DEBUG_READONLY_COW)
         /* only for simple PVs unblessed */
         if ( SvIsCOW(ref) && !SvOOK(ref) && SvLEN(ref) > 0 ) {
 
diff --git a/t/03scalar.t b/t/03scalar.t
index bbed4d1..a5cbeaf 100755
--- a/t/03scalar.t
+++ b/t/03scalar.t
@@ -8,13 +8,14 @@
 # (It may become useful if the test is moved to ./t subdirectory.)
 
 use B q{svref_2object};
+use B::COW;
 
 my $has_data_dumper;
 
 BEGIN {
   $| = 1;
   my $tests = 12;
-  $tests += 2 if $] > 5.0219;
+  $tests += 2 if B::COW::can_cow();
   eval q[use Data::Dumper];
   if (!$@) {
     $has_data_dumper = 1;
@@ -100,7 +101,7 @@ ok( $a != $b, '$a != $b' );
   ok( $c != $d, 'SV are differents SVs' );
 
 
-  if ( $] > 5.0219 ) {
+  if ( B::COW::can_cow() ) {
     my $sv_c = svref_2object( $c );
     my $sv_d = svref_2object( $d );