diff --git a/src/ConnectionPool.php b/src/ConnectionPool.php
index 5abb2d6..3c46b49 100644
--- a/src/ConnectionPool.php
+++ b/src/ConnectionPool.php
@@ -148,6 +148,10 @@ public function borrow()
      */
     public function return($connection): bool
     {
+        if (!$this->connector->validate($connection)) {
+            throw new \RuntimeException('Connection of unexpected type returned.');
+        }
+
         if (!$this->initialized) {
             throw new \RuntimeException('Please initialize the connection pool first, call $pool->init().');
         }
diff --git a/src/Connectors/ConnectorInterface.php b/src/Connectors/ConnectorInterface.php
index 538f571..e04e946 100644
--- a/src/Connectors/ConnectorInterface.php
+++ b/src/Connectors/ConnectorInterface.php
@@ -32,4 +32,12 @@ public function isConnected($connection): bool;
      * @return mixed
      */
     public function reset($connection, array $config);
+
+    /**
+     * Validate the connection
+     *
+     * @param mixed $connection
+     * @return bool
+     */
+    public function validate($connection): bool;
 }
\ No newline at end of file
diff --git a/src/Connectors/CoroutineMySQLConnector.php b/src/Connectors/CoroutineMySQLConnector.php
index dcc51fe..7b01c73 100644
--- a/src/Connectors/CoroutineMySQLConnector.php
+++ b/src/Connectors/CoroutineMySQLConnector.php
@@ -31,4 +31,9 @@ public function reset($connection, array $config)
     {
 
     }
+
+    public function validate($connection): bool
+    {
+        return $connection instanceof MySQL;
+    }
 }
\ No newline at end of file
diff --git a/src/Connectors/CoroutinePostgreSQLConnector.php b/src/Connectors/CoroutinePostgreSQLConnector.php
index 424efae..d3b6930 100644
--- a/src/Connectors/CoroutinePostgreSQLConnector.php
+++ b/src/Connectors/CoroutinePostgreSQLConnector.php
@@ -34,4 +34,9 @@ public function reset($connection, array $config)
     {
         /**@var PostgreSQL $connection */
     }
+
+    public function validate($connection): bool
+    {
+        return $connection instanceof PostgreSQL;
+    }
 }
\ No newline at end of file
diff --git a/src/Connectors/CoroutineRedisConnector.php b/src/Connectors/CoroutineRedisConnector.php
index 635b9ad..968e0a8 100644
--- a/src/Connectors/CoroutineRedisConnector.php
+++ b/src/Connectors/CoroutineRedisConnector.php
@@ -45,4 +45,9 @@ public function reset($connection, array $config)
         }
         $connection->setDefer(false);
     }
+
+    public function validate($connection): bool
+    {
+        return $connection instanceof Redis;
+    }
 }
\ No newline at end of file
diff --git a/src/Connectors/PhpRedisConnector.php b/src/Connectors/PhpRedisConnector.php
index 6e38da3..bbcb11a 100644
--- a/src/Connectors/PhpRedisConnector.php
+++ b/src/Connectors/PhpRedisConnector.php
@@ -45,4 +45,9 @@ public function reset($connection, array $config)
             $connection->select($config['database']);
         }
     }
+
+    public function validate($connection): bool
+    {
+        return $connection instanceof \Redis;
+    }
 }
\ No newline at end of file