diff --git a/tests/test_default_args.py b/tests/test_default_args.py
new file mode 100644
index 0000000..ed5b3bc
--- /dev/null
+++ b/tests/test_default_args.py
@@ -0,0 +1,45 @@
+from dataclasses import dataclass
+
+from src.breakshaft.convertor import ConvRepo
+
+
+@dataclass
+class A:
+    a: int
+
+
+@dataclass
+class B:
+    b: float
+
+
+type optC = str
+
+
+def test_default_consumer_args():
+    repo = ConvRepo()
+
+    @repo.mark_injector()
+    def b_to_a(b: B) -> A:
+        return A(int(b.b))
+
+    @repo.mark_injector()
+    def a_to_b(a: A) -> B:
+        return B(float(a.a))
+
+    @repo.mark_injector()
+    def int_to_a(i: int) -> A:
+        return A(i)
+
+    def consumer(dep: A, opt_dep: optC = '42') -> tuple[int, str]:
+        return dep.a, opt_dep
+
+    fn1 = repo.get_conversion((B,), consumer, force_commutative=True, force_async=False, allow_async=False)
+    dep = fn1(B(42.1))
+    assert dep == (42, '42')
+
+    fn2 = repo.get_conversion((int,), consumer, force_commutative=True, force_async=False, allow_async=False)
+    dep = fn2(123)
+    assert dep == (123, '42')
+
+