diff --git a/src/testFixtures/java/org/jastadd/relast/tests/RelAstProcessorTestBase.java b/src/testFixtures/java/org/jastadd/relast/tests/RelAstProcessorTestBase.java
index e83746c04a4a85327eabf5db0a1de580e6a42e3c..1cd91257d917426386a804f94279d58008f54136 100644
--- a/src/testFixtures/java/org/jastadd/relast/tests/RelAstProcessorTestBase.java
+++ b/src/testFixtures/java/org/jastadd/relast/tests/RelAstProcessorTestBase.java
@@ -169,8 +169,11 @@ public class RelAstProcessorTestBase {
     Assertions.assertTrue(baseDir.isDirectory());
     File[] files = baseDir.listFiles((FileFilter) FileFilterUtils.directoryFileFilter());
     Assertions.assertNotNull(files);
-    return Arrays.stream(files).map(File::toPath).map(f -> DynamicTest.dynamicTest(f.getFileName().toString(),
-        () -> directoryTest(mainClass, f)));
+    return Arrays.stream(files)
+        // TODO consider also supporting "config.yml"
+        .filter(f -> Objects.requireNonNull(f.listFiles(x -> x.getName().matches("config\\.yaml"))).length == 1)
+        .map(File::toPath)
+        .map(f -> DynamicTest.dynamicTest(f.getFileName().toString(), () -> directoryTest(mainClass, f)));
   }
 
 }