diff -bu Class-C3-Componentised-1.001000-2/lib/Class/C3/Componentised.pm~ Class-C3-Componentised-1.001000-2/lib/Class/C3/Componentised.pm
--- Class-C3-Componentised-1.001000-2/lib/Class/C3/Componentised.pm~	2011-08-09 05:27:52.000000000 +0200
+++ Class-C3-Componentised-1.001000-2/lib/Class/C3/Componentised.pm	2017-03-06 17:22:59.000000000 +0100
@@ -196,7 +196,13 @@
   for my $comp (reverse @_) {
     my $apply = do {
       no strict 'refs';
-      sub { unshift ( @{"${target}::ISA"}, $comp ) };
+      sub {
+        my $ro = Internals::SvREADONLY(@{"${target}::ISA"});
+        Internals::SvREADONLY(@{"${target}::ISA"}, 0) if $ro;
+        my @ret = unshift ( @{"${target}::ISA"}, $comp );
+        Internals::SvREADONLY(@{"${target}::ISA"}, 1) if $ro;
+        @ret
+      };
     };
     unless ($target eq $comp || $target->isa($comp)) {
       our %APPLICATOR_FOR;