diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4132973..886559c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## NOT RELEASED
 
+### Changed
+
+- Enable compiler optimization for the `sprintf` function.
+
 ## 1.5.4
 
 ### Changed
diff --git a/src/Input/PutEventsRequest.php b/src/Input/PutEventsRequest.php
index 2f29eb0..cfeca12 100644
--- a/src/Input/PutEventsRequest.php
+++ b/src/Input/PutEventsRequest.php
@@ -116,7 +116,7 @@ private function requestBody(): array
     {
         $payload = [];
         if (null === $v = $this->entries) {
-            throw new InvalidArgument(sprintf('Missing parameter "Entries" for "%s". The value cannot be null.', __CLASS__));
+            throw new InvalidArgument(\sprintf('Missing parameter "Entries" for "%s". The value cannot be null.', __CLASS__));
         }
 
         $index = -1;