diff --git a/src/peep/peep.c b/src/peep/peep.c
index 04668288a0..51bfe6b04d 100644
--- a/src/peep/peep.c
+++ b/src/peep/peep.c
@@ -426,6 +426,9 @@ static uint8 peep_assess_surroundings(sint16 center_x, sint16 center_y, sint16 c
 						break;
 
 					scenery = get_footpath_item_entry(footpath_element_get_path_scenery_index(mapElement));
+					if (scenery == NULL) {
+						return PEEP_THOUGHT_TYPE_NONE;
+					}
 					if (footpath_element_path_scenery_is_ghost(mapElement))
 						break;
 
@@ -10893,6 +10896,10 @@ money32 set_peep_name(int flags, int state, uint16 sprite_index, uint8* text_1,
 void game_command_set_guest_name(int *eax, int *ebx, int *ecx, int *edx, int *esi, int *edi, int *ebp) {
 	uint16 sprite_index = *ecx & 0xFFFF;
 
+	if (sprite_index >= MAX_SPRITES) {
+		*ebx = MONEY32_UNDEFINED;
+		return;
+	}
 	rct_peep *peep = GET_PEEP(sprite_index);
 	if (peep->type != PEEP_TYPE_GUEST) {
 		*ebx = MONEY32_UNDEFINED;
diff --git a/src/peep/staff.c b/src/peep/staff.c
index 4030f1ef90..64dc1ebb27 100644
--- a/src/peep/staff.c
+++ b/src/peep/staff.c
@@ -1236,6 +1236,10 @@ int staff_path_finding(rct_peep* peep) {
 void game_command_set_staff_name(int *eax, int *ebx, int *ecx, int *edx, int *esi, int *edi, int *ebp) {
 	uint16 sprite_index = *ecx & 0xFFFF;
 
+	if (sprite_index >= MAX_SPRITES) {
+		*ebx = MONEY32_UNDEFINED;
+		return;
+	}
 	rct_peep *peep = GET_PEEP(sprite_index);
 	if (peep->type != PEEP_TYPE_STAFF) {
 		*ebx = MONEY32_UNDEFINED;
diff --git a/src/ride/track_design.c b/src/ride/track_design.c
index 30434ecd79..2c134ceb14 100644
--- a/src/ride/track_design.c
+++ b/src/ride/track_design.c
@@ -1393,6 +1393,9 @@ static money32 place_track_design(sint16 x, sint16 y, sint16 z, uint8 flags, uin
 	}
 
 	rct_track_td6 *td6 = gActiveTrackDesign;
+	if (td6 == NULL) {
+		return MONEY32_UNDEFINED;
+	}
 	rct_object_entry *rideEntryObject = &td6->vehicle_object;
 
 	uint8 entryType, entryIndex;
diff --git a/src/windows/save_prompt.c b/src/windows/save_prompt.c
index ef88877004..60d0de0191 100644
--- a/src/windows/save_prompt.c
+++ b/src/windows/save_prompt.c
@@ -120,6 +120,10 @@ void window_save_prompt_open()
 	rct_widget *widgets;
 	uint64 enabled_widgets;
 
+	if (gSavePromptMode >= countof(window_save_prompt_labels)) {
+		log_warning("Invalid save prompt mode %u", gSavePromptMode);
+		return;
+	}
 	prompt_mode = gSavePromptMode;
 	if (prompt_mode == PM_QUIT)
 		prompt_mode = PM_SAVE_BEFORE_QUIT;