diff --git a/src/Frame.cpp b/src/Frame.cpp
index 7d8b5339..c14d66e0 100644
--- a/src/Frame.cpp
+++ b/src/Frame.cpp
@@ -37,7 +37,7 @@ void MoveFrame3(void)
 	else
 	{
 		// Widescreen/tallscreen-safe behaviour
-		if (map_w * 16 < WINDOW_WIDTH)
+		if ((map_w - 1) * 16 < WINDOW_WIDTH)
 		{
 			gFrame.x = -(((WINDOW_WIDTH - ((map_w - 1) * 16)) * 0x200) / 2);
 		}
@@ -52,7 +52,7 @@ void MoveFrame3(void)
 				gFrame.x = (((map_w - 1) * 16) - WINDOW_WIDTH) * 0x200;
 		}
 
-		if (map_l * 16 < WINDOW_HEIGHT)
+		if ((map_l - 1) * 16 < WINDOW_HEIGHT)
 		{
 			gFrame.y = -(((WINDOW_HEIGHT - ((map_l - 1) * 16)) * 0x200) / 2);
 		}