diff --git a/tests/test_val.py b/tests/test_val.py
index 0840b07..62b0e4c 100644
--- a/tests/test_val.py
+++ b/tests/test_val.py
@@ -114,7 +114,7 @@ def test_add_meters_seconds_fails():
     try:
         a + b  # type: ignore
         assert False
-    except SumDimensionsMismatch:
+    except SumDimensionsMismatchError:
         assert True
 
 
@@ -170,7 +170,7 @@ def test_sub_meters_seconds_fails():
     try:
         a - b  # type: ignore
         assert False
-    except SumDimensionsMismatch:
+    except SumDimensionsMismatchError:
         assert True