diff --git a/lib/Lacuna/DB/Result/Map/Body/Planet.pm b/lib/Lacuna/DB/Result/Map/Body/Planet.pm
index f4c45962..0650019c 100644
--- a/lib/Lacuna/DB/Result/Map/Body/Planet.pm
+++ b/lib/Lacuna/DB/Result/Map/Body/Planet.pm
@@ -700,7 +700,9 @@ has embassy => (
         );    
 
 sub is_space_free {
-    my ($self, $x, $y) = @_;
+    my ($self, $unclean_x, $unclean_y) = @_;
+    my $x = int( $unclean_x );
+    my $y = int( $unclean_y );
     my $count = grep {$_->x == $x and $_->y == $y} @{$self->building_cache};
     return 0 if $count > 0;
     return 1;
@@ -732,7 +734,9 @@ sub find_free_space {
 }
 
 sub check_for_available_build_space {
-    my ($self, $x, $y) = @_;
+    my ($self, $unclean_x, $unclean_y) = @_;
+    my $x = int( $unclean_x );
+    my $y = int( $unclean_y );
     if ($x > 5 || $x < -5 || $y > 5 || $y < -5) {
         confess [1009, "That's not a valid space for a building.", [$x, $y]];
     }
diff --git a/lib/Lacuna/RPC/Body.pm b/lib/Lacuna/RPC/Body.pm
index e7cb9dd1..ab6f5037 100644
--- a/lib/Lacuna/RPC/Body.pm
+++ b/lib/Lacuna/RPC/Body.pm
@@ -123,8 +123,8 @@ sub rearrange_buildings {
   my @miss_in_new; my @miss_in_cur;
   for my $building (@$arrangement) {
     my $id = $building->{id};
-    my $x  = $building->{x};
-    my $y  = $building->{y};
+    my $x  = int( $building->{x} );
+    my $y  = int( $building->{y} );
     $new_ids{$id} = {
       x     => $x,
       y     => $y,
diff --git a/lib/Lacuna/RPC/Building.pm b/lib/Lacuna/RPC/Building.pm
index 4a501b7f..71f655e1 100644
--- a/lib/Lacuna/RPC/Building.pm
+++ b/lib/Lacuna/RPC/Building.pm
@@ -137,10 +137,13 @@ sub view {
 }
 
 sub build {
-    my ($self, $session_id, $body_id, $x, $y) = @_;
+    my ($self, $session_id, $body_id, $unclean_x, $unclean_y) = @_;
     my $empire = $self->get_empire_by_session($session_id);
     my $body = $self->get_body($empire, $body_id);
 
+    my $x = int( $unclean_x );
+    my $y = int( $unclean_y );
+
     if ($x eq '' || $y eq '' || $x < -5 || $y < -5 || $x > 5 || $y > 5) {
             confess [1009, "You must specify an x,y coordinate to place the building that is between -5 and 5.", [$x, $y]];
     }
diff --git a/t/090_Build.t b/t/090_Build.t
index 9c990c3b..d01824e7 100644
--- a/t/090_Build.t
+++ b/t/090_Build.t
@@ -202,6 +202,12 @@ $water1->finish_upgrade;
 $water2->finish_upgrade;
 $water3->finish_upgrade;
 
+# Make sure non-integer coordinates don't work
+$result = $tester->post('waterpurification', 'build', [$session_id, $home_planet, '3.1', -3]);
+ok(exists $result->{error}, 'non-integer string attack thwarted!');
+$result = $tester->post('waterpurification', 'build', [$session_id, $home_planet, 3.2, -3]);
+ok(exists $result->{error}, 'non-integer number attack thwarted!');
+
 $home->add_plan('Lacuna::DB::Result::Building::SpacePort',1,4);
 $home->add_plan('Lacuna::DB::Result::Building::SpacePort',1);
 $home->add_plan('Lacuna::DB::Result::Building::SpacePort',1,3);