diff --git a/src/viewport.h b/src/viewport.h
--- a/src/viewport.h
+++ b/src/viewport.h
@@ -49,7 +49,7 @@ void OffsetGroundSprite(int x, int y);
 void DrawGroundSprite(SpriteID image, SpriteID pal);
 void DrawGroundSpriteAt(SpriteID image, SpriteID pal, int32 x, int32 y, byte z);
 void AddSortableSpriteToDraw(SpriteID image, SpriteID pal, int x, int y, int w, int h, byte dz, byte z);
-void *AddStringToDraw(int x, int y, StringID string, uint32 params_1, uint32 params_2);
+void *AddStringToDraw(int x, int y, StringID string, uint64 params_1, uint64 params_2);
 void AddChildSpriteScreen(SpriteID image, SpriteID pal, int x, int y);