diff --git a/phongo_version.h b/phongo_version.h
index 7356ba077..38727ac5f 100644
--- a/phongo_version.h
+++ b/phongo_version.h
@@ -22,9 +22,9 @@
  * publishing a release. */
 
 /* clang-format off */
-#define PHP_MONGODB_VERSION "1.20.0dev"
+#define PHP_MONGODB_VERSION "1.21.0dev"
 #define PHP_MONGODB_STABILITY "devel"
-#define PHP_MONGODB_VERSION_DESC 1,20,0,0
+#define PHP_MONGODB_VERSION_DESC 1,21,0,0
 /* clang-format on */
 
 #endif /* PHONGO_VERSION_H */
diff --git a/tests/utils/tools.php b/tests/utils/tools.php
index 07142cc32..76d822a18 100644
--- a/tests/utils/tools.php
+++ b/tests/utils/tools.php
@@ -602,7 +602,7 @@ function severityToString(int $severity): string {
         'E_USER_ERROR' => E_USER_ERROR,
         'E_USER_WARNING' => E_USER_WARNING,
         'E_USER_NOTICE' => E_USER_NOTICE,
-        'E_STRICT' => E_STRICT,
+        'E_STRICT' => 2048, // E_STRICT was deprecated in PHP 8.4
         'E_RECOVERABLE_ERROR' => E_RECOVERABLE_ERROR,
         'E_DEPRECATED' => E_DEPRECATED,
         'E_USER_DEPRECATED' => E_USER_DEPRECATED,