diff --git a/Netdisco/Changes b/Netdisco/Changes
index e6e22bfb..c1cac867 100644
--- a/Netdisco/Changes
+++ b/Netdisco/Changes
@@ -10,6 +10,7 @@
   * Return first port neighbor match, if multiple devices claim the IP (closes #42)
   * Should handle empty ports preferences (closes #39)
   * Decode more entPhysicalEntry columns as UTF-8 (closes #37)
+  * Lock device_port table when updating Device Ports (closes #40)
 
 2.018000 - 2013-10-08
 
diff --git a/Netdisco/lib/App/Netdisco/Core/Discover.pm b/Netdisco/lib/App/Netdisco/Core/Discover.pm
index 059653ab..364b7ede 100644
--- a/Netdisco/lib/App/Netdisco/Core/Discover.pm
+++ b/Netdisco/lib/App/Netdisco/Core/Discover.pm
@@ -282,7 +282,7 @@ sub store_interfaces {
       };
   }
 
-  schema('netdisco')->txn_do(sub {
+  schema('netdisco')->resultset('DevicePort')->txn_do_locked(sub {
     my $gone = $device->ports->delete({keep_nodes => 1});
     debug sprintf ' [%s] interfaces - removed %s interfaces',
       $device->ip, $gone;
diff --git a/Netdisco/lib/App/Netdisco/DB/ResultSet/DevicePort.pm b/Netdisco/lib/App/Netdisco/DB/ResultSet/DevicePort.pm
index 58b7ba55..29d3fa56 100644
--- a/Netdisco/lib/App/Netdisco/DB/ResultSet/DevicePort.pm
+++ b/Netdisco/lib/App/Netdisco/DB/ResultSet/DevicePort.pm
@@ -4,6 +4,10 @@ use base 'DBIx::Class::ResultSet';
 use strict;
 use warnings FATAL => 'all';
 
+__PACKAGE__->load_components(qw/
+  +App::Netdisco::DB::ExplicitLocking
+/);
+
 =head1 ADDITIONAL METHODS
 
 =head2 with_times