diff --git a/src/toolbar_gui.cpp b/src/toolbar_gui.cpp
--- a/src/toolbar_gui.cpp
+++ b/src/toolbar_gui.cpp
@@ -1113,7 +1113,7 @@ class NWidgetMainToolbarContainer : publ
 		};
 
 		/* If at least BIGGEST_ARRANGEMENT fit, just spread all the buttons nicely */
-		uint full_buttons = max((width + this->smallest_x - 1) / this->smallest_x, SMALLEST_ARRANGEMENT);
+		uint full_buttons = max(CeilDiv(width, this->smallest_x), SMALLEST_ARRANGEMENT);
 		if (full_buttons > BIGGEST_ARRANGEMENT) {
 			button_count = arrangable_count = lengthof(arrange_all);
 			spacer_count = this->spacers;