diff --git a/src/viewport.cpp b/src/viewport.cpp
--- a/src/viewport.cpp
+++ b/src/viewport.cpp
@@ -88,7 +88,6 @@
 #include "command_func.h"
 #include "network/network_func.h"
 #include "framerate_type.h"
-#include "core/sort_func.hpp"
 
 #include <map>
 
@@ -1380,22 +1379,11 @@ static bool ViewportSortParentSpritesChe
 	return true;
 }
 
-static int CDECL CompareParentSprites(ParentSpriteToDraw * const *psd, ParentSpriteToDraw * const *psd2)
-{
-	const ParentSpriteToDraw *ps = *psd;
-	const ParentSpriteToDraw *ps2 = *psd2;
-	return ps->xmin - ps2->xmin;
-}
-
 /** Sort parent sprites pointer array */
 static void ViewportSortParentSprites(ParentSpriteToSortVector *psdv)
 {
 	ParentSpriteToDraw **psdvend = psdv->End();
 	ParentSpriteToDraw **psd = psdv->Begin();
-
-	/* pre-sort by xmin in ascending order */
-	QSortT(psd, psdvend - psd, CompareParentSprites);
-
 	while (psd != psdvend) {
 		ParentSpriteToDraw *ps = *psd;
 
@@ -1432,11 +1420,9 @@ static void ViewportSortParentSprites(Pa
 				 * I.e. every single order of X, Y, Z says ps2 is behind ps or they overlap.
 				 * That is: If one partial order says ps behind ps2, do not change the order.
 				 */
-				if (ps->xmax < ps2->xmin) {
-					/* all following sprites have xmin >= ps2->xmin */
-					break;
-				}
-				if (ps->ymax < ps2->ymin || ps->zmax < ps2->zmin) {
+				if (ps->xmax < ps2->xmin ||
+						ps->ymax < ps2->ymin ||
+						ps->zmax < ps2->zmin) {
 					continue;
 				}
 			}