diff --git a/src/group_gui.cpp b/src/group_gui.cpp
--- a/src/group_gui.cpp
+++ b/src/group_gui.cpp
@@ -182,7 +182,7 @@ private:
 		}
 		this->tiny_step_height = max(this->tiny_step_height, this->column_size[VGC_PROFIT].height);
 
-		SetDParam(0, GroupStatistics::Get(this->vli.company, ALL_GROUP, this->vli.vtype).num_vehicle > 900 ? 9999 : 999);
+		SetDParamMaxValue(0, GroupStatistics::Get(this->vli.company, ALL_GROUP, this->vli.vtype).num_vehicle, 3);
 		this->column_size[VGC_NUMBER] = GetStringBoundingBox(STR_TINY_COMMA);
 		this->tiny_step_height = max(this->tiny_step_height, this->column_size[VGC_NUMBER].height);