diff --git a/rmgpy/rmg/model.py b/rmgpy/rmg/model.py
index 1ab45dc67c..994bdf5558 100644
--- a/rmgpy/rmg/model.py
+++ b/rmgpy/rmg/model.py
@@ -849,6 +849,8 @@ def process_new_reactions(self, new_reactions, new_species, pdep_network=None, g
                 pdep = rxn.generate_high_p_limit_kinetics()
             elif any([any([x.is_subgraph_isomorphic(q) for q in self.unrealgroups]) for y in rxn.reactants + rxn.products for x in y.molecule]):
                 pdep = False
+            elif not rxn.reversible:
+                pdep = False
 
             # If pressure dependence is on, we only add reactions that are not unimolecular;
             # unimolecular reactions will be added after processing the associated networks