diff --git a/src/drawing/drawing.h b/src/drawing/drawing.h
index cbab3b8eb3..b1da60712f 100644
--- a/src/drawing/drawing.h
+++ b/src/drawing/drawing.h
@@ -122,6 +122,8 @@ typedef struct rct_palette {
 
 #define PALETTE_TO_G1_OFFSET_COUNT 144
 
+#define MAX_SCROLLING_TEXT_MODES 38
+
 extern sint16 gCurrentFontSpriteBase;
 extern uint16 gCurrentFontFlags;
 
diff --git a/src/drawing/scrolling_text.c b/src/drawing/scrolling_text.c
index baa43b2072..b5597b9ead 100644
--- a/src/drawing/scrolling_text.c
+++ b/src/drawing/scrolling_text.c
@@ -1365,7 +1365,7 @@ static const sint16 _scrollpos37[] = {
 	-1,
 };
 
-static const sint16* _scrollPositions[38] = {
+static const sint16* _scrollPositions[MAX_SCROLLING_TEXT_MODES] = {
 	_scrollpos0,
 	_scrollpos1,
 	_scrollpos2,
@@ -1416,6 +1416,8 @@ static const sint16* _scrollPositions[38] = {
  */
 int scrolling_text_setup(rct_string_id stringId, uint16 scroll, uint16 scrollingMode)
 {
+	assert(scrollingMode < MAX_SCROLLING_TEXT_MODES);
+
 	rct_drawpixelinfo* dpi = unk_140E9A8;
 
 	if (dpi->zoom_level != 0) return SPR_SCROLLING_TEXT_DEFAULT;
diff --git a/src/paint/map_element/banner.c b/src/paint/map_element/banner.c
index 5a6d239045..81c7df4744 100644
--- a/src/paint/map_element/banner.c
+++ b/src/paint/map_element/banner.c
@@ -83,6 +83,10 @@ void banner_paint(uint8 direction, int height, rct_map_element* map_element)
 	if (direction >= 2 || (map_element->flags & MAP_ELEMENT_FLAG_GHOST)) return;
 
 	uint16 scrollingMode = banner_scenery->banner.scrolling_mode;
+	if (scrollingMode >= MAX_SCROLLING_TEXT_MODES) {
+		return;
+	}
+
 	scrollingMode += direction;
 
 	set_format_arg(0, uint32, 0);