diff --git a/src/main/java/com/wimbli/WorldBorder/BorderData.java b/src/main/java/com/wimbli/WorldBorder/BorderData.java
index 8217363..1b015d1 100644
--- a/src/main/java/com/wimbli/WorldBorder/BorderData.java
+++ b/src/main/java/com/wimbli/WorldBorder/BorderData.java
@@ -406,8 +406,13 @@ public class BorderData
 	// check if a particular spot consists of 2 breathable blocks over something relatively solid
 	private boolean isSafeSpot(World world, int X, int Y, int Z, boolean flying)
 	{
-		boolean safe = safeOpenBlocks.contains(world.getBlockAt(X, Y, Z).getType())		// target block open and safe
-					&& safeOpenBlocks.contains(world.getBlockAt(X, Y + 1, Z).getType());	// above target block open and safe
+		boolean safe =
+			// target block open and safe or is above maximum Y coordinate
+			(Y == world.getMaxHeight()
+			 || (safeOpenBlocks.contains(world.getBlockAt(X, Y, Z).getType())
+			     // above target block open and safe or is above maximum Y coordinate
+			     && (Y + 1 == world.getMaxHeight()
+				 || safeOpenBlocks.contains(world.getBlockAt(X, Y + 1, Z).getType()))));
 		if (!safe || flying)
 			return safe;
 
@@ -423,9 +428,10 @@ public class BorderData
 	// find closest safe Y position from the starting position
 	private double getSafeY(World world, int X, int Y, int Z, boolean flying)
 	{
-		// artificial height limit of 127 added for Nether worlds since CraftBukkit still incorrectly returns 255 for their max height, leading to players sent to the "roof" of the Nether
+		// artificial height limit of 127 added for Nether worlds since CraftBukkit still incorrectly returns 255 for their max height, leading to players sent to the "roof" of the Nether; we don't bother checking if Y = 126 or 127 are safe because they never will be unless there's a hole in the bedrock
 		final boolean isNether = world.getEnvironment() == World.Environment.NETHER;
-		int limTop = isNether ? 125 : world.getMaxHeight() - 2;
+		int limTop = isNether ? 125 : world.getMaxHeight();
+		// add 1 because getHighestBlockYAt() will give us the Y coordinate of a solid block, and we want the air block above it
 		final int highestBlockBoundary = Math.min(world.getHighestBlockYAt(X, Z) + 1, limTop);
 
 		// if Y is larger than the world can be and user can fly, return Y - Unless we are in the Nether, we might not want players on the roof
@@ -448,12 +454,13 @@ public class BorderData
 		if (Y < limBot)
 			Y = limBot;
 
-		// for non Nether worlds we don't need to check upwards to the world-limit, it is enough to check up to the highestBlockBoundary, unless player is flying
+		// for non Nether worlds we don't need to check upwards to the world-limit, it is enough to check up to and including the highestBlockBoundary, unless player is flying
 		if (!isNether && !flying)
 			limTop = highestBlockBoundary;
 		// Expanding Y search method adapted from Acru's code in the Nether plugin
 
-		for(int y1 = Y, y2 = Y; (y1 > limBot) || (y2 < limTop); y1--, y2++){
+		// Note that we want to include limTop in the search - in the extreme case, world.getMaxHeight() should be included since the player can stand on top of the highest block
+		for(int y1 = Y, y2 = Y; (y1 > limBot) || (y2 <= limTop); y1--, y2++){
 			// Look below.
 			if(y1 > limBot)
 			{
@@ -462,7 +469,7 @@ public class BorderData
 			}
 
 			// Look above.
-			if(y2 < limTop && y2 != y1)
+			if(y2 <= limTop && y2 != y1)
 			{
 				if (isSafeSpot(world, X, y2, Z, flying))
 					return (double)y2;