diff --git a/src/API/Common/Time/ClockInterface.php b/src/API/Common/Time/ClockInterface.php
index b4a953c11..115c10600 100644
--- a/src/API/Common/Time/ClockInterface.php
+++ b/src/API/Common/Time/ClockInterface.php
@@ -9,6 +9,7 @@ interface ClockInterface
     public const NANOS_PER_SECOND = 1_000_000_000;
     public const NANOS_PER_MILLISECOND = 1_000_000;
     public const NANOS_PER_MICROSECOND = 1_000;
+    public const MICROS_PER_MILLISECOND = 1_000;
     public const MILLIS_PER_SECOND = 1_000;
 
     /**
diff --git a/src/Contrib/Grpc/GrpcTransport.php b/src/Contrib/Grpc/GrpcTransport.php
index 0577ea81d..babc1ab16 100644
--- a/src/Contrib/Grpc/GrpcTransport.php
+++ b/src/Contrib/Grpc/GrpcTransport.php
@@ -18,6 +18,7 @@
 use const Grpc\OP_SEND_MESSAGE;
 use const Grpc\STATUS_OK;
 use Grpc\Timeval;
+use OpenTelemetry\API\Common\Time\ClockInterface;
 use OpenTelemetry\Contrib\Otlp\ContentTypes;
 use OpenTelemetry\SDK\Common\Export\TransportInterface;
 use OpenTelemetry\SDK\Common\Future\CancellationInterface;
@@ -49,7 +50,7 @@ public function __construct(
     ) {
         $this->channel = new Channel($endpoint, $opts);
         $this->metadata = $this->formatMetadata(array_change_key_case($headers));
-        $this->exportTimeout = new Timeval($timeoutMillis * 1000);
+        $this->exportTimeout = new Timeval($timeoutMillis * ClockInterface::MICROS_PER_MILLISECOND);
     }
 
     public function contentType(): string
diff --git a/src/Contrib/Grpc/GrpcTransportFactory.php b/src/Contrib/Grpc/GrpcTransportFactory.php
index 41661c034..4c03562f4 100644
--- a/src/Contrib/Grpc/GrpcTransportFactory.php
+++ b/src/Contrib/Grpc/GrpcTransportFactory.php
@@ -81,7 +81,7 @@ public function create(
             $opts,
             $method,
             $headers,
-            (int)($timeout * 1000),
+            (int) ($timeout * 1000),
         );
     }