diff --git a/bin/problem.py b/bin/problem.py
index 27aad5db..50699ee1 100644
--- a/bin/problem.py
+++ b/bin/problem.py
@@ -194,7 +194,9 @@ def get_testdata_yaml(p, path, key, name=None) -> str | None:
         if key == 'grading':
             raise NotImplementedError(key)
         if key != 'input_validator_flags' and name is not None:
-            raise ValueError(f"Only input validators support flags by validator name, got {key} and {name}")
+            raise ValueError(
+                f"Only input validators support flags by validator name, got {key} and {name}"
+            )
 
         for dir in [path] + list(path.parents):
             f = dir / 'testdata.yaml'
@@ -211,21 +213,23 @@ def get_testdata_yaml(p, path, key, name=None) -> str | None:
                             if isinstance(flags[key], str):
                                 continue
                             for name in flags[key]:
-                                input_validator_names = list(val.name for  val in p.validators(validate.InputValidator))
+                                input_validator_names = list(
+                                    val.name for val in p.validators(validate.InputValidator)
+                                )
                                 if not name in input_validator_names:
-                                    warn(f'Unknown input validator {name}; expected {input_validator_names}')
+                                    warn(
+                                        f'Unknown input validator {name}; expected {input_validator_names}'
+                                    )
                         case 'grading' | 'run_samples':
                             warn(f'{key} not implemented in BAPCtools')
                         case _:
                             warn(f'Unknown testdata.yaml key: {key}')
 
-
-                
                 # Store testdata.yaml files in a cache.
                 if f not in p._testdata_yamls:
                     p._testdata_yamls[f] = read_yaml(f, plain=True)
 
-                #flags = p._testdata_yamls[f] 
+                # flags = p._testdata_yamls[f]
                 if key in flags:
                     if isinstance(flags[key], str):
                         return flags[key]
diff --git a/bin/testcase.py b/bin/testcase.py
index 84a193af..5cfbef2b 100644
--- a/bin/testcase.py
+++ b/bin/testcase.py
@@ -116,9 +116,10 @@ def __init__(self, base_problem, path: Path, *, short_path=None):
         # Read using the short_path instead of the in_path, because during
         # generate the testcase will live in a temporary directory, where
         # testdata.yaml doesn't exist.
-        self.testdata_yaml = self.problem.get_testdata_yaml(
-            self.problem.path / 'data' / self.short_path
-        )
+
+        # self.testdata_yaml = self.problem.get_testdata_yaml( TODO Thore
+        # self.problem.path / 'data' / self.short_path
+        # )
 
     def __repr__(self):
         return self.name
@@ -128,7 +129,7 @@ def with_suffix(self, ext):
 
     def testdata_yaml_validator_flags(self, validator) -> list[str] | None | Literal[False]:
         """
-        The flags specified in testdata.yaml for the given validator,
+        The flags specified in testdata.yaml for the given validator applying to this testcase.
 
         Arguments
         ---------
@@ -150,19 +151,20 @@ def testdata_yaml_validator_flags(self, validator) -> list[str] | None | Literal
         if self.problem.settings.validation == 'default' and isinstance(validator, OutputValidator):
             return None
 
-        if self.testdata_yaml is None:
-            return None
-        key = (
-            'input_validator_flags'
-            if isinstance(validator, InputValidator)
-            else 'output_validator_flags'
-        )
-        if key not in self.testdata_yaml:
-            return None
-        flags = self.testdata_yaml[key]
+        if isinstance(validator, InputValidator):
+            key = 'input_validator_flags'
+            name = validator.name
+        else:
+            key = 'output_validator_flags'
+            name = None
+
+        path = self.problem.path / 'data' / self.short_path
+        flags = self.problem.get_testdata_yaml(path, key, name=name)
         # Note: support for lists/dicts for was removed in #259.
+        if flags is None:
+            return None
         if not isinstance(flags, str):
-            fatal(f'{key} must be a string in testdata.yaml')
+            fatal(f'{key} must be a string in testdata.yaml, got {flags}')
         return flags.split()
 
     def validator_hashes(self, cls: Type[Validator]):