diff --git a/mathics/builtin/numbers/constants.py b/mathics/builtin/numbers/constants.py
index e7833c371..2f4e4a1d6 100644
--- a/mathics/builtin/numbers/constants.py
+++ b/mathics/builtin/numbers/constants.py
@@ -757,6 +757,7 @@ class Underflow(Builtin):
     val = instance.get_constant()
     NUMERICAL_CONSTANTS[instance.symbol] = MachineReal(val.value)
 
+# Remove these variables to prevent errors in the SYMBOL_MANIFEST check.
 del cls
 del instance
 del val