fix.diff

diff --git a/src/gfx.cpp b/src/gfx.cpp
index b5267e42a..19c06471b 100644
--- a/src/gfx.cpp
+++ b/src/gfx.cpp
@@ -1800,8 +1800,8 @@ void CursorVars::UpdateCursorPositionRelative(int delta_x, int delta_y)
                int last_position_x = this->pos.x;
                int last_position_y = this->pos.y;
 
-               this->pos.x = Clamp(this->pos.x + delta_x, 0, _cur_resolution.width);
-               this->pos.y = Clamp(this->pos.y + delta_y, 0, _cur_resolution.height);
+               this->pos.x = Clamp(this->pos.x + delta_x, 0, _cur_resolution.width - 1);
+               this->pos.y = Clamp(this->pos.y + delta_y, 0, _cur_resolution.height - 1);
 
                this->delta.x = last_position_x - this->pos.x;
                this->delta.y = last_position_y - this->pos.y;