diff --git a/src/main/java/com/sk89q/worldguard/protection/regions/ProtectedPolygonalRegion.java b/src/main/java/com/sk89q/worldguard/protection/regions/ProtectedPolygonalRegion.java
index cff11ede..e712ab34 100644
--- a/src/main/java/com/sk89q/worldguard/protection/regions/ProtectedPolygonalRegion.java
+++ b/src/main/java/com/sk89q/worldguard/protection/regions/ProtectedPolygonalRegion.java
@@ -154,7 +154,7 @@ public class ProtectedPolygonalRegion extends ProtectedRegion {
             p2 = points.get(s);
 
             // Do the math, then reassign s
-            area += ((p2.getBlockX() + .5) + (p1.getBlockX() + .5)) * ((p2.getBlockZ() + .5) - (p1.getBlockZ() + .5));
+            area += (p2.getBlockX() + p1.getBlockX() + 1) * (p2.getBlockZ() - p1.getBlockZ());
             s = i;
         }
         return (int) Math.abs(Math.ceil(area / 2D) * yLength);