diff --git a/src/tr1/game/viewport.c b/src/tr1/game/viewport.c
index 6de38844e..98e3e2cb4 100644
--- a/src/tr1/game/viewport.c
+++ b/src/tr1/game/viewport.c
@@ -22,8 +22,8 @@ void Viewport_Init(int32_t x, int32_t y, int32_t width, int32_t height)
 {
     m_MinX = x;
     m_MinY = y;
-    m_MaxX = x + width - 1;
-    m_MaxY = y + height - 1;
+    m_MaxX = x + width;
+    m_MaxY = y + height;
     m_CenterX = (m_MinX + m_MaxX) / 2;
     m_CenterY = (m_MinY + m_MaxY) / 2;
     m_Width = width;