diff --git a/src/widgets/dropdown.cpp b/src/widgets/dropdown.cpp
index 6b0f60e..30cceaa 100644
--- a/src/widgets/dropdown.cpp
+++ b/src/widgets/dropdown.cpp
@@ -141,7 +141,7 @@ struct DropdownWindow : Window {
 		}
 
 		/* Capacity is the average number of items visible */
-		this->vscroll->SetCapacity(size.height * (uint16)list->Length() / list_height);
+		this->vscroll->SetCapacity(size.height * (uint16)list->Length() / max(1, list_height));
 		this->vscroll->SetCount((uint16)list->Length());
 
 		this->parent_wnd_class = parent->window_class;
@@ -373,8 +373,8 @@ void ShowDropDownListAt(Window *w, const DropDownList *list, int selected, int b
 		} else {
 			/* ... and lastly if it won't, enable the scroll bar and fit the
 			 * list in below the widget */
-			int avg_height = list_height / (int)list->Length();
-			int rows = (screen_bottom - 4 - top) / avg_height;
+			int avg_height = list_height / max((int)list->Length(), 1);
+			int rows = (screen_bottom - 4 - top) / max(avg_height, 1);
 			height = rows * avg_height;
 			scroll = true;
 			/* Add space for the scroll bar if we automatically determined