diff -u b/core/modules/update/src/ProjectCoreCompatibility.php b/core/modules/update/src/ProjectCoreCompatibility.php
--- b/core/modules/update/src/ProjectCoreCompatibility.php
+++ b/core/modules/update/src/ProjectCoreCompatibility.php
@@ -149,7 +149,7 @@
    *
    * @param string $core_compatibility_constraint
    *   A semantic version constraint.
-   * @param boolean $core_compatible
+   * @param bool $core_compatible
    *   Is the release compatible with the currently installed version of core?
    *
    * @return array