diff --git a/src/group_gui.cpp b/src/group_gui.cpp
index e28e10bb2c..0bf8589ac5 100644
--- a/src/group_gui.cpp
+++ b/src/group_gui.cpp
@@ -1017,6 +1017,7 @@ public:
 				}
 				this->groups.ForceRebuild();
 				this->BuildGroupList(this->owner);
+				this->group_sb->SetCount((uint)this->groups.size());
 				id_g = find_index(this->groups, g);
 			}
 			this->group_sb->ScrollTowards(id_g);