diff --git a/src/Tracing/Cache/TraceableCacheAdapterForV2.php b/src/Tracing/Cache/TraceableCacheAdapterForV2.php
index 7a5b57c9..6a0bdde5 100644
--- a/src/Tracing/Cache/TraceableCacheAdapterForV2.php
+++ b/src/Tracing/Cache/TraceableCacheAdapterForV2.php
@@ -40,7 +40,7 @@ public function __construct(HubInterface $hub, AdapterInterface $decoratedAdapte
      *
      * @return mixed
      */
-    public function get(string $key, callable $callback, float $beta = null, array &$metadata = null)
+    public function get(string $key, callable $callback, float $beta = null, array &$metadata = null): mixed
     {
         return $this->traceFunction('cache.get_item', function () use ($key, $callback, $beta, &$metadata) {
             if (!$this->decoratedAdapter instanceof CacheInterface) {
diff --git a/src/Tracing/Cache/TraceableTagAwareCacheAdapterForV2.php b/src/Tracing/Cache/TraceableTagAwareCacheAdapterForV2.php
index a89d911f..f9df4400 100644
--- a/src/Tracing/Cache/TraceableTagAwareCacheAdapterForV2.php
+++ b/src/Tracing/Cache/TraceableTagAwareCacheAdapterForV2.php
@@ -41,7 +41,7 @@ public function __construct(HubInterface $hub, TagAwareAdapterInterface $decorat
      *
      * @return mixed
      */
-    public function get(string $key, callable $callback, float $beta = null, array &$metadata = null)
+    public function get(string $key, callable $callback, float $beta = null, array &$metadata = null): mixed
     {
         return $this->traceFunction('cache.get_item', function () use ($key, $callback, $beta, &$metadata) {
             if (!$this->decoratedAdapter instanceof CacheInterface) {
diff --git a/src/Tracing/Doctrine/DBAL/TracingDriverConnection.php b/src/Tracing/Doctrine/DBAL/TracingDriverConnection.php
index b23dff90..82ede117 100644
--- a/src/Tracing/Doctrine/DBAL/TracingDriverConnection.php
+++ b/src/Tracing/Doctrine/DBAL/TracingDriverConnection.php
@@ -120,7 +120,7 @@ public function query(?string $sql = null, ...$args): Result
      *
      * @return mixed
      */
-    public function quote($value, $type = ParameterType::STRING)
+    public function quote($value, $type = ParameterType::STRING): mixed
     {
         return $this->decoratedConnection->quote($value, $type);
     }
@@ -140,7 +140,7 @@ public function exec($sql): int
      *
      * @return string|int|false
      */
-    public function lastInsertId($name = null)
+    public function lastInsertId($name = null): string|int|false
     {
         return $this->decoratedConnection->lastInsertId($name);
     }
diff --git a/src/Tracing/Doctrine/DBAL/TracingServerInfoAwareDriverConnection.php b/src/Tracing/Doctrine/DBAL/TracingServerInfoAwareDriverConnection.php
index de1270bd..fea68257 100644
--- a/src/Tracing/Doctrine/DBAL/TracingServerInfoAwareDriverConnection.php
+++ b/src/Tracing/Doctrine/DBAL/TracingServerInfoAwareDriverConnection.php
@@ -54,7 +54,7 @@ public function query(?string $sql = null, ...$args): Result
      *
      * @return mixed
      */
-    public function quote($value, $type = ParameterType::STRING)
+    public function quote($value, $type = ParameterType::STRING): mixed
     {
         return $this->decoratedConnection->quote($value, $type);
     }
@@ -72,7 +72,7 @@ public function exec($sql): int
      *
      * @return string|int|false
      */
-    public function lastInsertId($name = null)
+    public function lastInsertId($name = null): string|int|false
     {
         return $this->decoratedConnection->lastInsertId($name);
     }
diff --git a/tests/EventListener/Fixtures/UserWithoutIdentifierStub.php b/tests/EventListener/Fixtures/UserWithoutIdentifierStub.php
index b547df5d..dcc44618 100644
--- a/tests/EventListener/Fixtures/UserWithoutIdentifierStub.php
+++ b/tests/EventListener/Fixtures/UserWithoutIdentifierStub.php
@@ -31,4 +31,9 @@ public function getSalt(): ?string
     public function eraseCredentials(): void
     {
     }
+
+    public function getUserIdentifier(): string
+    {
+        return $this->getUsername();
+    }
 }