diff --git a/src/lang/polish.txt b/src/lang/polish.txt
--- a/src/lang/polish.txt
+++ b/src/lang/polish.txt
@@ -2756,6 +2756,8 @@ STR_NEWGRF_INSPECT_CAPTION_OBJECT_AT_RAI
 STR_NEWGRF_INSPECT_QUERY_CAPTION                                :{WHITE}NewGFR zmienna 60+parametr x (heksadecymalnie)
 
 # Sprite aligner window
+STR_SPRITE_ALIGNER_NEXT_BUTTON                                  :{BLACK}Następny sprite
+STR_SPRITE_ALIGNER_PREVIOUS_BUTTON                              :{BLACK}Poprzedni sprite
 
 
 # NewGRF (self) generated warnings/errors