diff --git a/Netdisco/Changes b/Netdisco/Changes
index d52a9fc3..314ede5c 100644
--- a/Netdisco/Changes
+++ b/Netdisco/Changes
@@ -14,6 +14,7 @@
 
   * [#85] device property in _no/_only fails with error (R. Kerr)
   * Also prefer port filter when linking to connected devices
+  * Fix SQL logic in PortMAC.pm (imperfectus)
 
 2.021001
 
diff --git a/Netdisco/lib/App/Netdisco/Util/PortMAC.pm b/Netdisco/lib/App/Netdisco/Util/PortMAC.pm
index b656e3a5..72836397 100644
--- a/Netdisco/lib/App/Netdisco/Util/PortMAC.pm
+++ b/Netdisco/lib/App/Netdisco/Util/PortMAC.pm
@@ -41,7 +41,7 @@ sub get_port_macs {
 
     my $dp_macs
         = schema('netdisco')->resultset('DevicePort')
-        ->search( { mac => { '!=', [ undef, '00:00:00:00:00:00' ] } },
+        ->search( { mac => { '!=' => [ -and => (undef, '00:00:00:00:00:00') ] } },
         { select => [ 'mac', 'ip' ],
           group_by => [ 'mac', 'ip' ] } );
     my $dp_cursor = $dp_macs->cursor;