diff --git a/includes/Api/ApiCoreThank.php b/includes/Api/ApiCoreThank.php
index 40384037..adf5adfa 100644
--- a/includes/Api/ApiCoreThank.php
+++ b/includes/Api/ApiCoreThank.php
@@ -33,7 +33,7 @@ class ApiCoreThank extends ApiThank {
 
 	public function __construct(
 		ApiMain $main,
-		$action,
+		string $action,
 		PermissionManager $permissionManager,
 		RevisionStore $revisionStore,
 		UserFactory $userFactory,
diff --git a/includes/Api/ApiFlowThank.php b/includes/Api/ApiFlowThank.php
index 5b3b0b01..eba7fe65 100644
--- a/includes/Api/ApiFlowThank.php
+++ b/includes/Api/ApiFlowThank.php
@@ -33,7 +33,7 @@ class ApiFlowThank extends ApiThank {
 
 	public function __construct(
 		ApiMain $main,
-		$action,
+		string $action,
 		PermissionManager $permissionManager,
 		LogStore $storage,
 		UserFactory $userFactory
diff --git a/includes/Api/ApiThank.php b/includes/Api/ApiThank.php
index 9c9f22e0..cd509e26 100644
--- a/includes/Api/ApiThank.php
+++ b/includes/Api/ApiThank.php
@@ -22,7 +22,7 @@ abstract class ApiThank extends ApiBase {
 
 	public function __construct(
 		ApiMain $main,
-		$action,
+		string $action,
 		PermissionManager $permissionManager,
 		LogStore $storage
 	) {