diff --git a/t/decode.t b/t/decode.t
new file mode 100644
index 0000000..277021f
--- /dev/null
+++ b/t/decode.t
@@ -0,0 +1,22 @@
+use strict;
+use Encode qw(decode_utf8 FB_CROAK);
+use Test::More tests => 3;
+
+sub croak_ok(&) {
+    my $code = shift;
+    eval { $code->() };
+    like $@, qr/does not map/;
+}
+
+my $bytes = "L\x{e9}on";
+my $pad = "\x{30C9}";
+
+my $orig = $bytes;
+croak_ok { Encode::decode_utf8($orig, FB_CROAK) };
+
+my $orig2 = $bytes;
+croak_ok { Encode::decode('utf-8', $orig2, FB_CROAK) };
+
+chop(my $new = $bytes . $pad);
+croak_ok { Encode::decode_utf8($new, FB_CROAK) };
+