diff --git a/src/Helpers/TelemetryHelper.php b/src/Helpers/TelemetryHelper.php
index 8512f86b3..141479c3d 100644
--- a/src/Helpers/TelemetryHelper.php
+++ b/src/Helpers/TelemetryHelper.php
@@ -107,7 +107,13 @@ public function initializeAmplitude(): void {
     }
   }
 
-  public static function normalizeAhEnv($ah_env): string {
+  /**
+   * @param string $ah_env
+   *   Environment name from AH_ENV.
+   * @return string
+   *   Normalized environment name.
+   */
+  public static function normalizeAhEnv(string $ah_env): string {
     if (AcquiaDrupalEnvironmentDetector::isAhProdEnv($ah_env)) {
       return 'prod';
     }
diff --git a/tests/phpunit/src/Misc/TelemetryHelperTest.php b/tests/phpunit/src/Misc/TelemetryHelperTest.php
index 14c473fba..611a9ca1a 100644
--- a/tests/phpunit/src/Misc/TelemetryHelperTest.php
+++ b/tests/phpunit/src/Misc/TelemetryHelperTest.php
@@ -67,6 +67,11 @@ public function testGetEnvironmentProviderWithoutAnyEnvSet(): void {
     // Expect null since no provider environment variables are set.
     $this->assertNull(TelemetryHelper::getEnvironmentProvider());
   }
+
+  /**
+   * @return mixed[]
+   *   The data provider.
+   */
   public function providerTestAhEnvNormalization(): array {
     return [
       ['prod', 'prod'],
@@ -81,8 +86,12 @@ public function providerTestAhEnvNormalization(): array {
 
   /**
    * @dataProvider providerTestAhEnvNormalization
+   * @param string $ah_env
+   *   The Acquia hosting environment.
+   * @param string $expected
+   *   The expected normalized environment.
    */
-  public function testAhEnvNormalization($ah_env, $expected) {
+  public function testAhEnvNormalization(string $ah_env, string $expected): void {
     $normalized_ah_env = TelemetryHelper::normalizeAhEnv($ah_env);
     $this->assertEquals($expected, $normalized_ah_env);
   }