diff --git a/server/gameserver/room.cc b/server/gameserver/room.cc
index 9ef2e29..cd6fb3b 100644
--- a/server/gameserver/room.cc
+++ b/server/gameserver/room.cc
@@ -464,8 +464,8 @@ void Room::UpdateGas()
                     (gas_data.pos_old - gas_data.pos_new).Norm();
                 float distance = gas_data.old_area_meta->i->shrink_speed() *
                     ((frame_no - gas_data.gas_start_frameno) * (1.0 / SERVER_FRAME_RATE));
-                gas_data.gas_progress = std::min(distance, total_distance);
-                if (std::abs(total_distance-distance) >= 0.001f) {
+                gas_data.gas_progress = std::min(total_distance - distance, 0.0f);
+                if (distance >= total_distance) {
                     int pre_area_id = gas_data.new_area_meta->i->id();
                     Vector2D pre_pos = gas_data.pos_new;
                     if (!MetaMgr::Instance()->GetSafeArea(pre_area_id + 1)) {
@@ -503,6 +503,9 @@ bool Room::GenSmallCircle(Vector2D big_circle_pos, float big_circle_rad, float s
     Vector2D dir = Vector2D::UP;
     dir.Rotate(a8::RandAngle());
     float rad = rand() % (int)(big_circle_rad - small_circle_rad);
+    if (rad <= 0.001f){
+        rad = 0.001f;
+    }
     out_pos = big_circle_pos + dir * rad;
     return true;
 }