diff --git a/plugins/greylisting b/plugins/greylisting
index efd5792..e7b3a02 100644
--- a/plugins/greylisting
+++ b/plugins/greylisting
@@ -474,7 +474,7 @@ sub prune_db {
 sub exclude {
     my ( $self ) = @_;
     return 1 if $self->is_immune();
-    return 1 if !$self->p0f_match();
+    return 1 if $self->{_args}{p0f} and ! $self->p0f_match();
     return 1 if $self->geoip_match();
     return 1 if $self->exclude_file_match();
     return;
diff --git a/t/plugin_tests/greylisting b/t/plugin_tests/greylisting
index 83a2be6..4576ecb 100644
--- a/t/plugin_tests/greylisting
+++ b/t/plugin_tests/greylisting
@@ -136,6 +136,16 @@ sub test_exclude {
     ok( $self->exclude(), "Relay client results in exclude() hit" );
     $self->connection->relay_client(0);
     ok( ! $self->exclude(), "Non-relay client results in exclude() miss" );
+
+    my $old_p0f = $self->connection->notes('p0f');
+    $self->connection->notes('p0f'=> { genre => 'windows' } );
+    delete $self->{_args}{p0f};
+    ok( ! $self->exclude(), 'no p0f args = no exclusion' );
+    $self->{_args}{'p0f'} = 'genre,Lindows';
+    ok(   $self->exclude(), 'p0f miss = exclusion' );
+    $self->{_args}{'p0f'} = 'genre,Windows';
+    ok( ! $self->exclude(), 'p0f hit = no exclusion' );
+    $self->connection->notes( p0f => $old_p0f );
 }
 
 sub test_greylist_geoip {