diff --git a/src/breakshaft/graph_walker.py b/src/breakshaft/graph_walker.py
index 1bdfc9d..2aa0aac 100644
--- a/src/breakshaft/graph_walker.py
+++ b/src/breakshaft/graph_walker.py
@@ -70,7 +70,7 @@ class GraphWalker:
 
                 if not dead_end:
 
-                    for opt, _ in point.opt_args:
+                    for opt in point.opt_args:
                         subg = cls.generate_callgraph_singletype(injectors,
                                                                  from_types,
                                                                  opt,
diff --git a/src/breakshaft/models.py b/src/breakshaft/models.py
index 0d1afb4..c49fc91 100644
--- a/src/breakshaft/models.py
+++ b/src/breakshaft/models.py
@@ -18,7 +18,7 @@ class ConversionPoint:
     fn: Callable
     injects: type
     requires: tuple[type, ...]
-    opt_args: tuple[tuple[type, object], ...]
+    opt_args: tuple[type, ...]
 
     def __hash__(self):
         return hash((self.fn, self.injects, self.requires))
@@ -67,15 +67,15 @@ class ConversionPoint:
 
         orig_argtypes = []
         for argname, argtype in orig_args:
-            orig_argtypes.append((argtype, argname in defaults.keys(), defaults.get(argname)))
+            orig_argtypes.append((argtype, argname in defaults.keys()))
 
-        default_map: list[tuple[bool, object]] = []
-        for argtype, has_default, default in orig_argtypes:
+        default_map: list[bool] = []
+        for argtype, has_default in orig_argtypes:
             if isinstance(argtype, types.UnionType) or get_origin(argtype) is Union:
                 u_types = list(get_args(argtype)) + [argtype]
             else:
                 u_types = [argtype]
-            default_map.append((has_default, default))
+            default_map.append(has_default)
             argtypes.append(u_types)
 
         argtype_combinations = all_combinations(argtypes)
@@ -83,9 +83,9 @@ class ConversionPoint:
         for argtype_combination in argtype_combinations:
             req_args = []
             opt_args = []
-            for argt, (has_default, default) in zip(argtype_combination, default_map):
+            for argt, has_default in zip(argtype_combination, default_map):
                 if has_default:
-                    opt_args.append((argt, default))
+                    opt_args.append(argt)
                 else:
                     req_args.append(argt)
             ret.append(ConversionPoint(func, rettype, tuple(req_args), tuple(opt_args)))
diff --git a/src/breakshaft/renderer.py b/src/breakshaft/renderer.py
index 8494e6b..ffe4b28 100644
--- a/src/breakshaft/renderer.py
+++ b/src/breakshaft/renderer.py
@@ -36,7 +36,7 @@ class ConversionRenderData:
             argname = argmap[arg_id][0]
             fnargs.append((argname, hashname(argtype)))
 
-        for arg_id, (argtype, _) in enumerate(inj.opt_args, len(inj.requires)):
+        for arg_id, argtype in enumerate(inj.opt_args, len(inj.requires)):
             argname = argmap[arg_id][0]
             if argtype in provided_types:
                 fnargs.append((argname, hashname(argtype)))