--- /dev/null
+#!perl
+use strict;
+use warnings FATAL => 'all';
+use Test::More;
+use Test::Fatal;
+
+{
+ package Foo;
+ use Function::Parameters qw(:strict);
+
+ method new($class:) { bless {}, $class }
+
+# method m1(:$bar!) { }
+# method m2(:$bar?) { }
+# method m3(:$bar ) { }
+
+# method m4( $bar!) { }
+ method m5( $bar = undef ) { }
+ method m6( $bar ) { }
+}
+
+my $foo = Foo->new;
+
+#is(exception { $foo->m1(bar => undef) }, undef, 'Explicitly pass undef to positional required arg');
+#is(exception { $foo->m2(bar => undef) }, undef, 'Explicitly pass undef to positional explicit optional arg');
+#is(exception { $foo->m3(bar => undef) }, undef, 'Explicitly pass undef to positional implicit optional arg');
+
+#is(exception { $foo->m4(undef) }, undef, 'Explicitly pass undef to required arg');
+is(exception { $foo->m5(undef) }, undef, 'Explicitly pass undef to explicit required arg');
+is(exception { $foo->m6(undef) }, undef, 'Explicitly pass undef to implicit required arg');
+
+done_testing;