diff --git a/tests/scripts/generate_tls13_compat_tests.py b/tests/scripts/generate_tls13_compat_tests.py
index 77f3374..05d80a5 100755
--- a/tests/scripts/generate_tls13_compat_tests.py
+++ b/tests/scripts/generate_tls13_compat_tests.py
@@ -67,10 +67,10 @@
     'secp521r1': 0x19,
     'x25519': 0x1d,
     'x448': 0x1e,
+    # Only one finite field group to keep testing time within reasonable bounds.
     'ffdhe2048': 0x100,
 }
 
-
 class TLSProgram:
     """
     Base class for generate server/client command.