diff --git a/src/viewport.cpp b/src/viewport.cpp
index 8be0cedc81..bf1f34acd6 100644
--- a/src/viewport.cpp
+++ b/src/viewport.cpp
@@ -1718,6 +1718,32 @@ void ViewportDoDraw(const Viewport *vp, int left, int top, int right, int bottom
 	_vd.child_screen_sprites_to_draw.clear();
 }
 
+/**
+ * Make sure we don't draw a too big area at a time.
+ * If we do, the sprite memory will overflow.
+ */
+static void ViewportDrawChk(const Viewport *vp, int left, int top, int right, int bottom)
+{
+	if ((int64)ScaleByZoom(bottom - top, vp->zoom) * (int64)ScaleByZoom(right - left, vp->zoom) > (int64)(180000 * ZOOM_LVL_BASE * ZOOM_LVL_BASE)) {
+		if ((bottom - top) > (right - left)) {
+			int t = (top + bottom) >> 1;
+			ViewportDrawChk(vp, left, top, right, t);
+			ViewportDrawChk(vp, left, t, right, bottom);
+		} else {
+			int t = (left + right) >> 1;
+			ViewportDrawChk(vp, left, top, t, bottom);
+			ViewportDrawChk(vp, t, top, right, bottom);
+		}
+	} else {
+		ViewportDoDraw(vp,
+			ScaleByZoom(left - vp->left, vp->zoom) + vp->virtual_left,
+			ScaleByZoom(top - vp->top, vp->zoom) + vp->virtual_top,
+			ScaleByZoom(right - vp->left, vp->zoom) + vp->virtual_left,
+			ScaleByZoom(bottom - vp->top, vp->zoom) + vp->virtual_top
+		);
+	}
+}
+
 static inline void ViewportDraw(const Viewport *vp, int left, int top, int right, int bottom)
 {
 	if (right <= vp->left || bottom <= vp->top) return;
@@ -1732,12 +1758,7 @@ static inline void ViewportDraw(const Viewport *vp, int left, int top, int right
 	if (top < vp->top) top = vp->top;
 	if (bottom > vp->top + vp->height) bottom = vp->top + vp->height;
 
-	ViewportDoDraw(vp,
-		ScaleByZoom(left - vp->left, vp->zoom) + vp->virtual_left,
-		ScaleByZoom(top - vp->top, vp->zoom) + vp->virtual_top,
-		ScaleByZoom(right - vp->left, vp->zoom) + vp->virtual_left,
-		ScaleByZoom(bottom - vp->top, vp->zoom) + vp->virtual_top
-	);
+	ViewportDrawChk(vp, left, top, right, bottom);
 }
 
 /**