diff --git a/jetnet/evaluation/gen_metrics.py b/jetnet/evaluation/gen_metrics.py
index 30092bf..0052282 100644
--- a/jetnet/evaluation/gen_metrics.py
+++ b/jetnet/evaluation/gen_metrics.py
@@ -707,10 +707,10 @@ def fpd(
             stacklevel=2,
         )
 
-    real_features, gen_features = _check_get_ndarray(real_features, gen_features)
+    X, Y = _check_get_ndarray(real_features, gen_features)
 
     if normalise:
-        X, Y = _normalise_features(real_features, gen_features)
+        X, Y = _normalise_features(X, Y)
 
     # regular intervals in 1/N
     batches = (1 / np.linspace(1.0 / min_samples, 1.0 / max_samples, num_points)).astype("int32")
@@ -836,10 +836,10 @@ def kpd(
     Returns:
         Tuple[float, float]: median and error of KPD.
     """
-    real_features, gen_features = _check_get_ndarray(real_features, gen_features)
+    X, Y = _check_get_ndarray(real_features, gen_features)
 
     if normalise:
-        X, Y = _normalise_features(real_features, gen_features)
+        X, Y = _normalise_features(X, Y)
 
     if num_threads is None:
         vals_point = _kpd_batches(X, Y, num_batches, batch_size, seed)
diff --git a/tests/evaluation/test_gen_metrics.py b/tests/evaluation/test_gen_metrics.py
index 285dbc8..533a1f9 100644
--- a/tests/evaluation/test_gen_metrics.py
+++ b/tests/evaluation/test_gen_metrics.py
@@ -7,6 +7,7 @@
 
 test_zeros = np.zeros((50_000, 2))
 test_ones = np.ones((50_000, 2))
+test_twos = np.ones((50_000, 2)) * 2
 
 
 def test_fpd():
@@ -14,12 +15,25 @@ def test_fpd():
     assert val == approx(0, abs=0.01)
     assert err < 1e-3
 
-    val, err = evaluation.fpd(test_zeros, test_ones)
-    assert val == approx(2, rel=0.01)
+    val, err = evaluation.fpd(test_twos, test_zeros)
+    assert val == approx(2, rel=0.01)  # 1^2 + 1^2
+    assert err < 1e-3
+    
+    # test normalization
+    val, err = evaluation.fpd(test_zeros, test_zeros, normalise=False)  # should have no effect
+    assert val == approx(0, abs=0.01)
+    assert err < 1e-3
+    
+    val, err = evaluation.fpd(test_twos, test_zeros, normalise=False)
+    assert val == approx(8, rel=0.01)  # 2^2 + 2^2
     assert err < 1e-3
 
 
 @pytest.mark.parametrize("num_threads", [None, 2])  # test numba parallelization
 def test_kpd(num_threads):
     assert evaluation.kpd(test_zeros, test_zeros, num_threads=num_threads) == approx([0, 0])
-    assert evaluation.kpd(test_zeros, test_ones, num_threads=num_threads) == approx([15, 0])
+    assert evaluation.kpd(test_twos, test_zeros, num_threads=num_threads) == approx([15, 0])
+    
+    # test normalization
+    assert evaluation.kpd(test_zeros, test_zeros, normalise=False, num_threads=num_threads) == approx([0, 0])
+    assert evaluation.kpd(test_twos, test_zeros, normalise=False, num_threads=num_threads) == approx([624, 0])
\ No newline at end of file