diff --git a/model.py b/model.py
index ffebfb1..429a26e 100644
--- a/model.py
+++ b/model.py
@@ -360,7 +360,7 @@ def model_closure(initial_set: Set[ModelValue], mfunctions: Set[ModelFunction],
     return closure_set
 
 
-def model_equivalence(model1: Model, model2: Model) -> bool:
+def model_equivalence(model1: Model, model2: Model, ignore_constants: bool = False) -> bool:
     """
     Takes two models and determines if they are equivalent.
     Assumes for the model to be equilvalent that their
@@ -373,8 +373,17 @@ def model_equivalence(model1: Model, model2: Model) -> bool:
     if model1.designated_values != model2.designated_values:
         return False
 
-    model1_fn_names = set((fn.operation_name for fn in model1.logical_operations))
-    model2_fn_names = set((fn.operation_name for fn in model2.logical_operations))
+    model1_fn_names = set()
+    for fn in model1.logical_operations:
+        if fn.arity == 0 and ignore_constants:
+            continue
+        model1_fn_names.add(fn.operation_name)
+
+    model2_fn_names = set()
+    for fn in model2.logical_operations:
+        if fn.arity == 0 and ignore_constants:
+            continue
+        model2_fn_names.add(fn.operation_name)
 
     if model1_fn_names != model2_fn_names:
         return False
diff --git a/utils/compare_vsp_results.py b/utils/compare_vsp_results.py
index daee3c5..82c587d 100644
--- a/utils/compare_vsp_results.py
+++ b/utils/compare_vsp_results.py
@@ -26,6 +26,7 @@ if __name__ == "__main__":
     parser = argparse.ArgumentParser(description="Compare models that have VSP in two ugly files")
     parser.add_argument("ugly1", type=str, help="First ugly data file")
     parser.add_argument("ugly2", type=str, help="Second ugly data file")
+    parser.add_argument("--ignore-constants", action='store_true', help="When it comes to model equivalance, ignore constants")
     args = vars(parser.parse_args())
 
     data_file1 = open(args['ugly1'], "r")
@@ -36,6 +37,8 @@ if __name__ == "__main__":
     solutions2 = parse_matrices(SourceFile(data_file2))
     solutions2 = list(restructure_solutions(solutions2, None))
 
+    ignore_constants = args.get("ignore_constants", False)
+
     # Total count of models
     total_models1 = 0
     total_models2 = 0
@@ -62,7 +65,7 @@ if __name__ == "__main__":
             # Check to see if model exists in file 2
             match_found_index = (False, -1)
             for i in range(len(solutions2) - 1, -1, -1):
-                if model_equivalence(model, solutions2[i][0]):
+                if model_equivalence(model, solutions2[i][0], ignore_constants):
                     match_found_index = (True, i)
                     break