diff --git a/contributors.md b/contributors.md
index a9d2eacb27..c4af6a2e87 100644
--- a/contributors.md
+++ b/contributors.md
@@ -138,6 +138,7 @@ The following people are not part of the development team, but have been contrib
 * Kevin Laframboise (klaframboise)
 * Tushar Sariya (TusharSariya)
 * (WantDiscussion)
+* Tomáš Žilínek (TomasZilinek)
 
 ## Toolchain
 * (Balletie) - macOS
diff --git a/src/openrct2/actions/SetCheatAction.hpp b/src/openrct2/actions/SetCheatAction.hpp
index b3b65aaac2..a3038fa3a5 100644
--- a/src/openrct2/actions/SetCheatAction.hpp
+++ b/src/openrct2/actions/SetCheatAction.hpp
@@ -642,7 +642,7 @@ private:
 
     void RemoveAllGuests() const
     {
-        uint16_t spriteIndex, nextSpriteIndex;
+        uint16_t spriteIndex;
         for (auto& ride : GetRideManager())
         {
             ride.num_riders = 0;
@@ -685,14 +685,10 @@ private:
             }
         }
 
-        for (spriteIndex = gSpriteListHead[SPRITE_LIST_PEEP]; spriteIndex != SPRITE_INDEX_NULL; spriteIndex = nextSpriteIndex)
+        Peep* peep;
+        FOR_ALL_GUESTS (spriteIndex, peep)
         {
-            auto peep = &(get_sprite(spriteIndex)->peep);
-            nextSpriteIndex = peep->next;
-            if (peep->type == PEEP_TYPE_GUEST)
-            {
-                peep->Remove();
-            }
+            peep->Remove();
         }
 
         window_invalidate_by_class(WC_RIDE);
diff --git a/src/openrct2/actions/StaffSetColourAction.hpp b/src/openrct2/actions/StaffSetColourAction.hpp
index dd5f6aacb6..b47214dc6b 100644
--- a/src/openrct2/actions/StaffSetColourAction.hpp
+++ b/src/openrct2/actions/StaffSetColourAction.hpp
@@ -67,9 +67,9 @@ public:
         // Update each staff member's uniform
         int32_t spriteIndex;
         Peep* peep;
-        FOR_ALL_PEEPS (spriteIndex, peep)
+        FOR_ALL_STAFF (spriteIndex, peep)
         {
-            if (peep->type == PEEP_TYPE_STAFF && peep->staff_type == _staffType)
+            if (peep->staff_type == _staffType)
             {
                 peep->tshirt_colour = _colour;
                 peep->trousers_colour = _colour;
diff --git a/src/openrct2/peep/Peep.cpp b/src/openrct2/peep/Peep.cpp
index 70d77a7c36..616135486e 100644
--- a/src/openrct2/peep/Peep.cpp
+++ b/src/openrct2/peep/Peep.cpp
@@ -404,18 +404,18 @@ int32_t peep_get_staff_count()
  */
 void peep_update_all()
 {
-    int32_t i;
+    int32_t i = 0;
     uint16_t spriteIndex;
     Peep* peep;
 
     if (gScreenFlags & SCREEN_FLAGS_EDITOR)
         return;
 
-    spriteIndex = gSpriteListHead[SPRITE_LIST_PEEP];
-    i = 0;
-    while (spriteIndex != SPRITE_INDEX_NULL)
+    // Do not use the FOR_ALL_PEEPS macro for this as next sprite index
+    // will be fetched on a delted peep if peep leaves the park.
+    for (spriteIndex = gSpriteListHead[SPRITE_LIST_PEEP]; spriteIndex != SPRITE_INDEX_NULL;)
     {
-        peep = &(get_sprite(spriteIndex)->peep);
+        peep = GET_PEEP(spriteIndex);
         spriteIndex = peep->next;
 
         if ((uint32_t)(i & 0x7F) != (gCurrentTicks & 0x7F))
diff --git a/src/openrct2/peep/Staff.cpp b/src/openrct2/peep/Staff.cpp
index aff8d6d7f7..2b24a1c1f2 100644
--- a/src/openrct2/peep/Staff.cpp
+++ b/src/openrct2/peep/Staff.cpp
@@ -143,6 +143,7 @@ bool staff_hire_new_member(STAFF_TYPE staffType, ENTERTAINER_COSTUME entertainer
 void staff_update_greyed_patrol_areas()
 {
     Peep* peep;
+    uint16_t sprite_index;
 
     for (int32_t staff_type = 0; staff_type < STAFF_TYPE_COUNT; ++staff_type)
     {
@@ -152,12 +153,9 @@ void staff_update_greyed_patrol_areas()
             gStaffPatrolAreas[staffPatrolOffset + i] = 0;
         }
 
-        for (uint16_t sprite_index = gSpriteListHead[SPRITE_LIST_PEEP]; sprite_index != SPRITE_INDEX_NULL;
-             sprite_index = peep->next)
+        FOR_ALL_STAFF (sprite_index, peep)
         {
-            peep = GET_PEEP(sprite_index);
-
-            if (peep->type == PEEP_TYPE_STAFF && staff_type == peep->staff_type)
+            if (peep->staff_type == staff_type)
             {
                 int32_t peepPatrolOffset = peep->staff_id * STAFF_PATROL_AREA_SIZE;
                 for (int32_t i = 0; i < STAFF_PATROL_AREA_SIZE; i++)