diff --git a/pyed/tests/test_operator_utils.py b/pyed/tests/test_operator_utils.py
index dc1f654..b8e1a65 100644
--- a/pyed/tests/test_operator_utils.py
+++ b/pyed/tests/test_operator_utils.py
@@ -13,7 +13,7 @@
 
 from triqs.operators import n, c, c_dag, Operator, dagger
 
-from triqs.operators.util.U_matrix import U_matrix_kanamori, U_matrix
+from triqs.operators.util.U_matrix import U_matrix_kanamori
 from triqs.operators.util.hamiltonians import h_int_kanamori
 
 from transform_kanamori import h_int_kanamori_transformed