diff --git a/lib/Test/Deep/Type.pm b/lib/Test/Deep/Type.pm
index 0a60f89..ead6b75 100644
--- a/lib/Test/Deep/Type.pm
+++ b/lib/Test/Deep/Type.pm
@@ -31,7 +31,10 @@ sub descend
 sub diag_message
 {
     my ($self, $where) = @_;
-    return "Validating $where as a " . $self->_type_name($self->{type}) . ' type';
+    my $name = $self->_type_name($self->{type});
+    return "Validating $where as a"
+        . (defined $name ? ' ' . $name : 'n unknown')
+        . ' type';
 }
 
 # we do not define a diagnostics sub, so we get the one produced by deep_diag
@@ -82,7 +85,7 @@ sub _type_name
     return $class if defined $class;
 
     # plain old subref perhaps?
-    return 'unknown type';
+    return;
 }
 
 1;
diff --git a/t/01-basic.t b/t/01-basic.t
index 0f307c6..e5138bd 100644
--- a/t/01-basic.t
+++ b/t/01-basic.t
@@ -2,7 +2,7 @@ use strict;
 use warnings FATAL => 'all';
 
 use Test::Tester 0.108;
-use Test::More tests => 33;
+use Test::More tests => 47;
 use Test::NoWarnings 1.04 ':early';
 use Test::Deep;
 use Test::Deep::Type;
@@ -41,10 +41,27 @@ ok(TypeHiLite->('hi'), 'validation succeeds (no error)');
 ok(!TypeHiLite->('hello'), 'validation fails with a simple bool');
 
 
+# the next type is a plain old unblessed coderef, returning a simple boolean
+# "did this validate"
+sub TypeHiTiny
+{
+    sub {
+        my $val = shift;
+        return if not defined $val;
+        return 1 if $val eq 'hi';   # validated: no error
+        return;
+    };
+}
+
+ok(TypeHiTiny->('hi'), 'validation succeeds (no error)');
+ok(!TypeHiTiny->('hello'), 'validation fails with a simple bool');
+
+
 check_tests(
     sub {
         cmp_deeply({ greeting => 'hi' }, { greeting => is_type(TypeHi) }, 'hi validates as a TypeHi');
         cmp_deeply({ greeting => 'hi' }, { greeting => is_type(TypeHiLite) }, 'hi validates as a TypeHiLite');
+        cmp_deeply({ greeting => 'hi' }, { greeting => is_type(TypeHiTiny) }, 'hi validates as a TypeHiTiny');
     },
     [ map { +{
         actual_ok => 1,
@@ -52,7 +69,7 @@ check_tests(
         diag => '',
         name => "hi validates as a $_",
         type => '',
-    } } qw(TypeHi TypeHiLite) ],
+    } } qw(TypeHi TypeHiLite TypeHiTiny) ],
     'validation successful',
 );
 
@@ -61,6 +78,9 @@ my ($premature, @results) = run_tests(
     sub {
         cmp_deeply({ greeting => 'hello' }, { greeting => is_type(TypeHi) }, 'hello validates as a TypeHi?');
         cmp_deeply({ greeting => 'hello' }, { greeting => is_type(TypeHiLite) }, 'hello validates as a TypeHiLite?');
+        cmp_deeply({ greeting => 'hello' }, { greeting => is_type(TypeHiTiny) }, 'hello validates as a TypeHiTiny?');
+# TODO
+#        cmp_deeply({ greeting => 'hello' }, { greeting => is_type('not a ref!') }, 'hello validates against an arbitrary subref?');
     },
 );
 
@@ -87,6 +107,17 @@ EOM
 Validating \$data->{"greeting"} as a TypeHiLite type
    got : failed
 expect : no error
+EOM
+        },
+        {
+            actual_ok => 0,
+            ok => 0,
+            name => "hello validates as a TypeHiTiny?",
+            type => '',
+            diag => <<EOM,
+Validating \$data->{"greeting"} as an unknown type
+   got : failed
+expect : no error
 EOM
         },
     ],