diff --git a/docs/Development.pod b/docs/Development.pod
index 15d09ecb..b93f68fa 100644
--- a/docs/Development.pod
+++ b/docs/Development.pod
@@ -126,9 +126,15 @@ A session ID,
 
 The ID of the development ministry.
 
-=head3 scheduled_id (required)
+=head3 scheduled_id (optional)
+
+The ID, or array of IDs, of the building(s) scheduled to be build/upgraded that you wish to cancel.
+
+=head3 cancel_all (optional)
+
+If set to a true value, cancels all builds currently scheduled.
 
-The ID of the building scheduled to be build/upgraded that you wish to cancel.
+One of C<scheduled_id> and C<cancel_all> is required.
 
 =head3 RESPONSE
 
diff --git a/lib/Lacuna/RPC/Building/Development.pm b/lib/Lacuna/RPC/Building/Development.pm
index b009636c..448c55b0 100644
--- a/lib/Lacuna/RPC/Building/Development.pm
+++ b/lib/Lacuna/RPC/Building/Development.pm
@@ -90,6 +90,8 @@ sub subsidize_one_build {
     };
 }
 
+my %non_cancel = map { $_=>1 } ('Lacuna::DB::Result::Building::DeployedBleeder');
+
 sub cancel_build {
     my ($self, $args) = @_;
 
@@ -99,21 +101,39 @@ sub cancel_build {
     my $session  = $self->get_session({session_id => $args->{session_id}, building_id => $args->{building_id} });
     my $empire   = $session->current_empire;
     my $building = $session->current_building;
-    my $scheduled_building  = $self->get_building($session,$args->{scheduled_id},nocheck_type=>1);
-    if (!$scheduled_building) {
-        confess [1003, "That building does not exist, or is not yours."];
-    }
-    if ($scheduled_building->body_id != $building->body_id) {
-        confess [1003, "That building is not on the same planet as your development ministry."];
+
+    my $ids = $args->{scheduled_id};
+    if ($ids && not ref $ids) {
+        $ids = [ $ids ];
     }
-    if (not $scheduled_building->is_upgrading) {
-        confess [1000, "That building is not currently being ugraded."];
+
+    my @order;
+    if ($args->{cancel_all}) {
+        @order = reverse @{$building->body->builds};
     }
-    my @non_cancel = ('Lacuna::DB::Result::Building::DeployedBleeder');
-    if (grep { $scheduled_building->class eq "$_" } @non_cancel) {
-        confess [1003, "That building can not have an upgrade cancelled."];
+    else {
+        @order = sort { $b->upgrade_ends cmp $a->upgrade_ends } map {
+            my $scheduled_id = $_;
+            my $scheduled_building = ref $scheduled_id ?
+                $scheduled_id :
+                $self->get_building($session,$scheduled_id,nocheck_type=>1);
+
+            if (!$scheduled_building) {
+                confess [1003, "That building does not exist, or is not yours."];
+            }
+            if ($scheduled_building->body_id != $building->body_id) {
+                confess [1003, "That building is not on the same planet as your development ministry."];
+            }
+            if (not $scheduled_building->is_upgrading) {
+                confess [1000, "That building is not currently being ugraded."];
+            }
+            if ($non_cancel{$scheduled_building->class}) {
+                confess [1003, "That building can not have an upgrade cancelled."];
+            }
+            $scheduled_building;
+        } @$ids;
     }
-    $scheduled_building->cancel_upgrade;
+    $_->cancel_upgrade for @order;
 
     return $self->view($args->{session_id}, $args->{building_id});
 
diff --git a/var/www/public/changes.txt b/var/www/public/changes.txt
index c490441b..e487ee5f 100644
--- a/var/www/public/changes.txt
+++ b/var/www/public/changes.txt
@@ -3,6 +3,8 @@
  - Fix: Some of the numbers in the APIs are now returned as numbers instead of strings.
  - Mod: Add commas to total cargo in TM and SST.
  - Fix: Initialize date_created field for spies.
+ - Mod: Can cancel more than one build at a time via API.
+ - Add: Cancel All button to dev ministry.
 
 3.0917:
  - Fix: Recalc stats when building 1+x plans.