diff --git a/src/danog/MadelineProto/Connection.php b/src/danog/MadelineProto/Connection.php
index f583b416..dfd0cc79 100644
--- a/src/danog/MadelineProto/Connection.php
+++ b/src/danog/MadelineProto/Connection.php
@@ -541,6 +541,7 @@ class Connection extends Session
                 $this->API->logger->logger($e);
             }
         }
+        $this->shared->signalDisconnect($this->id);
         $this->API->logger->logger("Disconnected from DC {$this->datacenterId}");
     }
 
diff --git a/src/danog/MadelineProto/DataCenter.php b/src/danog/MadelineProto/DataCenter.php
index 841f4bf0..8aaa692d 100644
--- a/src/danog/MadelineProto/DataCenter.php
+++ b/src/danog/MadelineProto/DataCenter.php
@@ -555,7 +555,7 @@ class DataCenter
 
                 return true;
             } catch (\Throwable $e) {
-                if (\defined('MADELINEPROTO_TEST') && MADELINEPROTO_TEST === 'pony') {
+                if (\defined(\MADELINEPROTO_TEST::class) && MADELINEPROTO_TEST === 'pony') {
                     throw $e;
                 }
                 $this->API->logger->logger('Connection failed: '.$e->getMessage(), \danog\MadelineProto\Logger::ERROR);
diff --git a/src/danog/MadelineProto/DataCenterConnection.php b/src/danog/MadelineProto/DataCenterConnection.php
index e2f804c7..9fb09b49 100644
--- a/src/danog/MadelineProto/DataCenterConnection.php
+++ b/src/danog/MadelineProto/DataCenterConnection.php
@@ -397,14 +397,37 @@ class DataCenterConnection implements JsonSerializable
         $ctx = $this->ctx->getCtx();
         $count += $previousCount = \count($this->connections);
         for ($x = $previousCount; $x < $count; $x++) {
+            $connection = new Connection();
+            $connection->setExtra($this, $x);
+            yield $connection->connect($ctx);
+
+            $this->connections[$x] = $connection;
             $this->availableConnections[$x] = 0;
-            $this->connections[$x] = new Connection();
-            $this->connections[$x]->setExtra($this, $x);
-            yield $this->connections[$x]->connect($ctx);
             $ctx = $this->ctx->getCtx();
         }
     }
 
+    /**
+     * Signal that a connection ID disconnected.
+     *
+     * @param integer $id Connection ID
+     *
+     * @return void
+     */
+    public function signalDisconnect(int $id)
+    {
+        $backup = $this->connections[$id]->backupSession();
+        $list = '';
+        foreach ($backup as $message) {
+            $list .= $message['_'] ?? '-';
+            $list .= ', ';
+        }
+        $this->API->logger->logger("Backed up $list from DC {$this->datacenter}.$id");
+        $this->backup = \array_merge($this->backup, $backup);
+
+        unset($this->connections[$id], $this->availableConnections[$id]);
+    }
+
     /**
      * Close all connections to DC.
      *
@@ -418,18 +441,11 @@ class DataCenterConnection implements JsonSerializable
             $this->robinLoop = null;
         }
         $before = \count($this->backup);
-        $list = '';
         foreach ($this->connections as $connection) {
-            $backup = $connection->backupSession();
-            foreach ($backup as $message) {
-                $list .= $message['_'] ?? '-';
-                $list .= ', ';
-            }
-            $this->backup = \array_merge($this->backup, $backup);
             $connection->disconnect();
         }
         $count = \count($this->backup) - $before;
-        $this->API->logger->logger("Backed up $count (added {$list}to $before existing messages) from DC {$this->datacenter}");
+        $this->API->logger->logger("Backed up $count, added to $before existing messages) from DC {$this->datacenter}");
 
         $this->connections = [];
         $this->availableConnections = [];
diff --git a/src/danog/MadelineProto/Stream/Proxy/SocksProxy.php b/src/danog/MadelineProto/Stream/Proxy/SocksProxy.php
index fe50dba6..197416bf 100644
--- a/src/danog/MadelineProto/Stream/Proxy/SocksProxy.php
+++ b/src/danog/MadelineProto/Stream/Proxy/SocksProxy.php
@@ -32,6 +32,17 @@ use danog\MadelineProto\Stream\RawProxyStreamInterface;
  */
 class SocksProxy implements RawProxyStreamInterface, BufferedProxyStreamInterface
 {
+    const REPS = [
+        0 => 'succeeded', 
+        1 => 'general SOCKS server failure', 
+        2 => 'connection not allowed by ruleset', 
+        3 => 'Network unreachable', 
+        4 => 'Host unreachable', 
+        5 => 'Connection refused', 
+        6 => 'TTL expired', 
+        7 => 'Command not supported', 
+        8 => 'Address type not supported'
+    ];
     use RawStream;
     private $extra;
 
@@ -105,6 +116,7 @@ class SocksProxy implements RawProxyStreamInterface, BufferedProxyStreamInterfac
 
         $rep = \ord(yield $buffer->bufferRead(1));
         if ($rep !== 0) {
+            $rep = self::REPS[$rep] ?? $rep;
             throw new \danog\MadelineProto\Exception("Wrong SOCKS5 rep: $rep");
         }