diff --git a/indra/statements/statements.py b/indra/statements/statements.py
index 6df7a9d631..f1db8f9781 100644
--- a/indra/statements/statements.py
+++ b/indra/statements/statements.py
@@ -1022,62 +1022,50 @@ class Demethylation(RemoveModification):
 
 class Carboxylation(AddModification):
     """Carboxylation modification."""
-    pass
 
 
 class Decarboxylation(RemoveModification):
     """Decarboxylation modification."""
-    pass
 
 
 class Amidation(AddModification):
     """Amidation modification."""
-    pass
 
 
 class Deamidation(RemoveModification):
     """Deamidation modification."""
-    pass
 
 
 class Sulfation(AddModification):
     """Sulfation modification."""
-    pass
 
 
 class Desulfation(RemoveModification):
     """Desulfation modification."""
-    pass
 
 
 class Neddylation(AddModification):
     """Neddylation modification."""
-    pass
 
 
 class Deneddylation(RemoveModification):
     """Deneddylation modification."""
-    pass
 
 
 class Alkylation(AddModification):
     """Alkylation modification."""
-    pass
 
 
 class Dealkylation(RemoveModification):
     """Dealkylation modification."""
-    pass
 
 
 class Prenylation(AddModification):
     """Prenylation modification."""
-    pass
 
 
 class Deprenylation(RemoveModification):
     """Deprenylation modification."""
-    pass
 
 
 @python_2_unicode_compatible