diff --git a/lib/pool.js b/lib/pool.js
index db54a7ab76..04eed3c1fa 100644
--- a/lib/pool.js
+++ b/lib/pool.js
@@ -203,7 +203,12 @@ class Pool extends EventEmitter {
           Date.now() - this._freeConnections.get(0).lastActiveTime >
             this.config.idleTimeout
         ) {
-          this._freeConnections.get(0).destroy();
+          const freeConnection = this._freeConnections.get(0)
+          
+          if (!freeConnection._pool) {
+            this._removeConnection(freeConnection);
+          }
+          freeConnection.destroy();
         }
       } finally {
         this._removeIdleTimeoutConnections();