diff --git a/rpn b/rpn
index 70606be..5dafafb 100755
--- a/rpn
+++ b/rpn
@@ -41,6 +41,12 @@ while (<>) {
 	} elsif (m{^ld$}) {
 	    my $x = pop @stack;
 	    push @stack, log($x) / log(2);
+	} elsif (m{^0x[0-9a-fA-F]+$}) {
+            no warnings 'portable';
+	    push @stack, hex($_);
+	} elsif (m{^0[0-7]+$}) {
+            no warnings 'portable';
+	    push @stack, oct($_);
 	} else {
 	    push @stack, $_;
 	}