diff --git a/src/game.c b/src/game.c
index 37ce64cc66..85bac97427 100644
--- a/src/game.c
+++ b/src/game.c
@@ -180,6 +180,22 @@ void game_logic_update()
 static void game_handle_input_mouse();
 static void game_get_next_input(int *x, int *y, int *state);
 
+static void RCT2_CALLPROC_EVENT_HANDLER(int address, rct_window* w)
+{
+	__asm {
+		push address
+			push w
+			mov eax, 0
+			mov ebx, 0
+			mov ecx, 0
+			mov edx, 0
+			mov esi, w
+			mov edi, 0
+			mov ebp, 0
+			call[esp+4]
+			add esp, 8
+	}
+}
 /**
  * 
  *  rct2: 0x006EA627
@@ -195,7 +211,7 @@ void game_handle_input()
 
 	if (RCT2_GLOBAL(0x009ABDF2, uint8) != 0) {
 		for (w = RCT2_ADDRESS(RCT2_ADDRESS_WINDOW_LIST, rct_window); w < RCT2_GLOBAL(RCT2_ADDRESS_NEW_WINDOW_PTR, rct_window*); w++)
-			RCT2_CALLPROC_X(w->event_handlers[WE_UNKNOWN_07], 0, 0, 0, 0, (int)w, 0, 0);
+			RCT2_CALLPROC_EVENT_HANDLER(w->event_handlers[WE_UNKNOWN_07], w);
 
 		RCT2_CALLPROC_EBPSAFE(0x006EA73F);
 		RCT2_CALLPROC_EBPSAFE(0x006E8346); // update_cursor_position
@@ -229,7 +245,7 @@ void game_handle_input()
 	}
 
 	for (w = RCT2_ADDRESS(RCT2_ADDRESS_WINDOW_LIST, rct_window); w < RCT2_GLOBAL(RCT2_ADDRESS_NEW_WINDOW_PTR, rct_window*); w++)
-		RCT2_CALLPROC_X(w->event_handlers[WE_UNKNOWN_08], 0, 0, 0, 0, (int)w, 0, 0);
+		RCT2_CALLPROC_EVENT_HANDLER(w->event_handlers[WE_UNKNOWN_08],w);
 }
 
 /**
diff --git a/src/window.c b/src/window.c
index 1b995f32f8..5638beee35 100644
--- a/src/window.c
+++ b/src/window.c
@@ -99,7 +99,22 @@ rct_widget *window_get_scroll_widget(rct_window *w, int scrollIndex)
 
 	return NULL;
 }
-
+static void RCT2_CALLPROC_EVENT_HANDLER(int address, rct_window* w)
+{
+	__asm {
+		push address
+			push w
+			mov eax, 0
+			mov ebx, 0
+			mov ecx, 0
+			mov edx, 0
+			mov esi, w
+			mov edi, 0
+			mov ebp, 0
+			call[esp + 4]
+			add esp, 8
+	}
+}
 /**
  * 
  *  rct2: 0x006ED7B0
@@ -111,7 +126,7 @@ void window_dispatch_update_all()
 	RCT2_GLOBAL(0x01423604, sint32)++;
 	RCT2_GLOBAL(RCT2_ADDRESS_TOOLTIP_NOT_SHOWN_TICKS, sint16)++;
 	for (w = RCT2_LAST_WINDOW; w >= RCT2_FIRST_WINDOW; w--)
-		RCT2_CALLPROC_X(w->event_handlers[WE_UPDATE], 0, 0, 0, 0, (int)w, 0, 0);
+		RCT2_CALLPROC_EVENT_HANDLER(w->event_handlers[WE_UPDATE], w);
 
 	RCT2_CALLPROC_EBPSAFE(0x006EE411);	// handle_text_input
 }
@@ -142,7 +157,7 @@ void window_update_all()
 	if (RCT2_GLOBAL(0x009DEB7C, sint16) >= 1000) {
 		RCT2_GLOBAL(0x009DEB7C, sint16) = 0;
 		for (w = RCT2_LAST_WINDOW; w >= RCT2_FIRST_WINDOW; w--)
-			RCT2_CALLPROC_X(w->event_handlers[WE_UNKNOWN_07], 0, 0, 0, 0, (int)w, 0, 0);
+			RCT2_CALLPROC_EVENT_HANDLER(w->event_handlers[WE_UNKNOWN_07],w);
 	}
 
 	// Border flash invalidation
diff --git a/src/window_cheats.c b/src/window_cheats.c
index 8dfbb32e21..3de5cf69c9 100644
--- a/src/window_cheats.c
+++ b/src/window_cheats.c
@@ -241,11 +241,11 @@ static void window_cheats_guests_mouseup()
 	}
 }
 
-static void window_cheats_update()
+static void window_cheats_update(rct_window *w)
 {
-	rct_window *w;
+	rct_window *w2;
 
-	__asm mov w, esi
+	__asm mov w2, esi
 
 	w->var_48E++;
 	widget_invalidate(w->classification, w->number, WIDX_TAB_1+w->page);