diff --git a/lib/Doctrine/DBAL/Sharding/PoolingShardManager.php b/lib/Doctrine/DBAL/Sharding/PoolingShardManager.php
index d0efce31ab2..5a21944d303 100644
--- a/lib/Doctrine/DBAL/Sharding/PoolingShardManager.php
+++ b/lib/Doctrine/DBAL/Sharding/PoolingShardManager.php
@@ -18,7 +18,7 @@ class PoolingShardManager implements ShardManager
     /** @var ShardChoser */
     private $choser;
 
-    /** @var string|null */
+    /** @var mixed */
     private $currentDistributionValue;
 
     public function __construct(PoolingShardConnection $conn)
@@ -31,7 +31,7 @@ public function __construct(PoolingShardConnection $conn)
     /**
      * {@inheritDoc}
      */
-    public function selectGlobal()
+    public function selectGlobal() : void
     {
         $this->conn->connect(0);
         $this->currentDistributionValue = null;
@@ -40,7 +40,7 @@ public function selectGlobal()
     /**
      * {@inheritDoc}
      */
-    public function selectShard($distributionValue)
+    public function selectShard($distributionValue) : void
     {
         $shardId = $this->choser->pickShard($distributionValue, $this->conn);
         $this->conn->connect($shardId);
@@ -58,7 +58,7 @@ public function getCurrentDistributionValue()
     /**
      * {@inheritDoc}
      */
-    public function getShards()
+    public function getShards() : array
     {
         $params = $this->conn->getParams();
         $shards = [];
@@ -75,7 +75,7 @@ public function getShards()
      *
      * @throws RuntimeException
      */
-    public function queryAll($sql, array $params, array $types)
+    public function queryAll(string $sql, array $params, array $types) : array
     {
         $shards = $this->getShards();
         if (! $shards) {
diff --git a/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureFederationsSynchronizer.php b/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureFederationsSynchronizer.php
index c372f416fca..343b941a6ec 100644
--- a/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureFederationsSynchronizer.php
+++ b/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureFederationsSynchronizer.php
@@ -158,7 +158,7 @@ public function dropAllSchema() : void
     /**
      * @return Schema[]
      */
-    private function partitionSchema(Schema $schema)
+    private function partitionSchema(Schema $schema) : array
     {
         return [
             $this->extractSchemaFederation($schema, false),
@@ -167,13 +167,9 @@ private function partitionSchema(Schema $schema)
     }
 
     /**
-     * @param bool $isFederation
-     *
-     * @return Schema
-     *
      * @throws RuntimeException
      */
-    private function extractSchemaFederation(Schema $schema, $isFederation)
+    private function extractSchemaFederation(Schema $schema, bool $isFederation) : Schema
     {
         $partitionedSchema = clone $schema;
 
@@ -204,7 +200,7 @@ private function extractSchemaFederation(Schema $schema, $isFederation)
      *
      * @return string[]
      */
-    private function work(Schema $schema, Closure $operation)
+    private function work(Schema $schema, Closure $operation) : array
     {
         [$global, $federation] = $this->partitionSchema($schema);
         $sql                   = [];
@@ -235,10 +231,7 @@ private function work(Schema $schema, Closure $operation)
         return $sql;
     }
 
-    /**
-     * @return string
-     */
-    private function getFederationTypeDefaultValue()
+    private function getFederationTypeDefaultValue() : string
     {
         $federationType = Type::getType($this->shardManager->getDistributionType());
 
@@ -259,10 +252,7 @@ private function getFederationTypeDefaultValue()
         return $defaultValue;
     }
 
-    /**
-     * @return string
-     */
-    private function getCreateFederationStatement()
+    private function getCreateFederationStatement() : string
     {
         $federationType    = Type::getType($this->shardManager->getDistributionType());
         $federationTypeSql = $federationType->getSQLDeclaration([], $this->conn->getDatabasePlatform());
diff --git a/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureShardManager.php b/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureShardManager.php
index ad5964a66e9..3463f4f09ba 100644
--- a/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureShardManager.php
+++ b/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureShardManager.php
@@ -35,7 +35,7 @@ class SQLAzureShardManager implements ShardManager
     /** @var Connection */
     private $conn;
 
-    /** @var string|null */
+    /** @var mixed */
     private $currentDistributionValue;
 
     /**
@@ -66,50 +66,40 @@ public function __construct(Connection $conn)
 
     /**
      * Gets the name of the federation.
-     *
-     * @return string
      */
-    public function getFederationName()
+    public function getFederationName() : string
     {
         return $this->federationName;
     }
 
     /**
      * Gets the distribution key.
-     *
-     * @return string
      */
-    public function getDistributionKey()
+    public function getDistributionKey() : string
     {
         return $this->distributionKey;
     }
 
     /**
      * Gets the Doctrine Type name used for the distribution.
-     *
-     * @return string
      */
-    public function getDistributionType()
+    public function getDistributionType() : string
     {
         return $this->distributionType;
     }
 
     /**
      * Sets Enabled/Disable filtering on the fly.
-     *
-     * @param bool $flag
-     *
-     * @return void
      */
-    public function setFilteringEnabled($flag)
+    public function setFilteringEnabled(bool $flag) : void
     {
-        $this->filteringEnabled = (bool) $flag;
+        $this->filteringEnabled = $flag;
     }
 
     /**
      * {@inheritDoc}
      */
-    public function selectGlobal()
+    public function selectGlobal() : void
     {
         if ($this->conn->isTransactionActive()) {
             throw ActiveTransaction::new();
@@ -123,7 +113,7 @@ public function selectGlobal()
     /**
      * {@inheritDoc}
      */
-    public function selectShard($distributionValue)
+    public function selectShard($distributionValue) : void
     {
         if ($this->conn->isTransactionActive()) {
             throw ActiveTransaction::new();
@@ -153,7 +143,7 @@ public function getCurrentDistributionValue()
     /**
      * {@inheritDoc}
      */
-    public function getShards()
+    public function getShards() : array
     {
         $sql = 'SELECT member_id as id,
                       distribution_name as distribution_key,
@@ -169,7 +159,7 @@ public function getShards()
      /**
       * {@inheritDoc}
       */
-    public function queryAll($sql, array $params = [], array $types = [])
+    public function queryAll(string $sql, array $params = [], array $types = []) : array
     {
         $shards = $this->getShards();
         if (! $shards) {
@@ -199,10 +189,8 @@ public function queryAll($sql, array $params = [], array $types = [])
      * Splits Federation at a given distribution value.
      *
      * @param mixed $splitDistributionValue
-     *
-     * @return void
      */
-    public function splitFederation($splitDistributionValue)
+    public function splitFederation($splitDistributionValue) : void
     {
         $type = Type::getType($this->distributionType);
 
diff --git a/lib/Doctrine/DBAL/Sharding/SQLAzure/Schema/MultiTenantVisitor.php b/lib/Doctrine/DBAL/Sharding/SQLAzure/Schema/MultiTenantVisitor.php
index da5328aed8f..a14f26c2418 100644
--- a/lib/Doctrine/DBAL/Sharding/SQLAzure/Schema/MultiTenantVisitor.php
+++ b/lib/Doctrine/DBAL/Sharding/SQLAzure/Schema/MultiTenantVisitor.php
@@ -54,11 +54,9 @@ class MultiTenantVisitor implements Visitor
     private $distributionName;
 
     /**
-     * @param string[]    $excludedTables
-     * @param string      $tenantColumnName
-     * @param string|null $distributionName
+     * @param string[] $excludedTables
      */
-    public function __construct(array $excludedTables = [], $tenantColumnName = 'tenant_id', $distributionName = null)
+    public function __construct(array $excludedTables = [], string $tenantColumnName = 'tenant_id', ?string $distributionName = null)
     {
         $this->excludedTables   = $excludedTables;
         $this->tenantColumnName = $tenantColumnName;
@@ -94,13 +92,9 @@ public function acceptTable(Table $table) : void
     }
 
     /**
-     * @param Table $table
-     *
-     * @return Index
-     *
      * @throws RuntimeException
      */
-    private function getClusteredIndex($table)
+    private function getClusteredIndex(Table $table) : Index
     {
         foreach ($table->getIndexes() as $index) {
             if ($index->isPrimary() && ! $index->hasFlag('nonclustered')) {
diff --git a/lib/Doctrine/DBAL/Sharding/ShardManager.php b/lib/Doctrine/DBAL/Sharding/ShardManager.php
index 793b0bb9340..d06f08ec331 100644
--- a/lib/Doctrine/DBAL/Sharding/ShardManager.php
+++ b/lib/Doctrine/DBAL/Sharding/ShardManager.php
@@ -27,26 +27,22 @@ interface ShardManager
      *
      * This is the default database that is connected when no shard is
      * selected.
-     *
-     * @return void
      */
-    public function selectGlobal();
+    public function selectGlobal() : void;
 
     /**
      * Selects the shard against which the queries after this statement will be issued.
      *
-     * @param string $distributionValue
-     *
-     * @return void
+     * @param mixed $distributionValue
      *
      * @throws ShardingException If no value is passed as shard identifier.
      */
-    public function selectShard($distributionValue);
+    public function selectShard($distributionValue) : void;
 
     /**
      * Gets the distribution value currently used for sharding.
      *
-     * @return string|null
+     * @return mixed
      */
     public function getCurrentDistributionValue();
 
@@ -58,7 +54,7 @@ public function getCurrentDistributionValue();
      *
      * @return mixed[][]
      */
-    public function getShards();
+    public function getShards() : array;
 
     /**
      * Queries all shards in undefined order and return the results appended to
@@ -66,11 +62,10 @@ public function getShards();
      *
      * Using {@link \Doctrine\DBAL\Connection::fetchAll} to retrieve rows internally.
      *
-     * @param string         $sql
      * @param mixed[]        $params
      * @param int[]|string[] $types
      *
      * @return mixed[]
      */
-    public function queryAll($sql, array $params, array $types);
+    public function queryAll(string $sql, array $params, array $types) : array;
 }