diff --git a/scripts/mbedtls_dev/test_generation.py b/scripts/mbedtls_dev/test_generation.py
index 00d559af6a..6382a99133 100644
--- a/scripts/mbedtls_dev/test_generation.py
+++ b/scripts/mbedtls_dev/test_generation.py
@@ -51,7 +51,7 @@ class BaseTarget(metaclass=ABCMeta):
     """
     count = 0
     case_description = ""
-    dependencies: List[str] = []
+    dependencies = [] # type: List[str]
     target_basename = ""
     test_function = ""
     test_name = ""