diff --git a/src/openrct2-ui/windows/TopToolbar.cpp b/src/openrct2-ui/windows/TopToolbar.cpp
index 731c59c138..1ae68f82a4 100644
--- a/src/openrct2-ui/windows/TopToolbar.cpp
+++ b/src/openrct2-ui/windows/TopToolbar.cpp
@@ -814,11 +814,16 @@ static void window_top_toolbar_invalidate(rct_window *w)
         window_top_toolbar_widgets[WIDX_MUTE].image = IMAGE_TYPE_REMAP | SPR_G2_TOOLBAR_UNMUTE;
 
     // Zoomed out/in disable. Not sure where this code is in the original.
-    if (window_get_main()->viewport->zoom == 0){
+    if (window_get_main()->viewport->zoom == 0)
+    {
         w->disabled_widgets |= (1 << WIDX_ZOOM_IN);
-    } else if (window_get_main()->viewport->zoom == 3){
+    }
+    else if (window_get_main()->viewport->zoom >= MAX_ZOOM_LEVEL)
+    {
         w->disabled_widgets |= (1 << WIDX_ZOOM_OUT);
-    } else {
+    }
+    else
+    {
         w->disabled_widgets &= ~((1 << WIDX_ZOOM_IN) | (1 << WIDX_ZOOM_OUT));
     }
 }
diff --git a/src/openrct2/interface/viewport.h b/src/openrct2/interface/viewport.h
index eb639e07dc..4143e62a27 100644
--- a/src/openrct2/interface/viewport.h
+++ b/src/openrct2/interface/viewport.h
@@ -88,6 +88,7 @@ typedef struct viewport_interaction_info {
 } viewport_interaction_info;
 
 #define MAX_VIEWPORT_COUNT WINDOW_LIMIT_MAX
+#define MAX_ZOOM_LEVEL 3
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/src/openrct2/interface/window.c b/src/openrct2/interface/window.c
index e53e7620eb..d3841ce263 100644
--- a/src/openrct2/interface/window.c
+++ b/src/openrct2/interface/window.c
@@ -1511,7 +1511,7 @@ void window_zoom_set(rct_window *w, sint32 zoomLevel, bool atCursor)
 {
     rct_viewport* v = w->viewport;
 
-    zoomLevel = clamp(0, zoomLevel, 3);
+    zoomLevel = clamp(0, zoomLevel, MAX_ZOOM_LEVEL);
     if (v->zoom == zoomLevel)
         return;