diff --git a/docs/matrices.rst b/docs/matrices.rst
index 1fba53db0..49e9b2bb4 100644
--- a/docs/matrices.rst
+++ b/docs/matrices.rst
@@ -63,3 +63,4 @@ Properties of Matrices and Vectors
     toqito.matrix_props.is_unitary
     toqito.matrix_props.majorizes
     toqito.matrix_props.sk_operator_norm
+    toqito.matrix_props.trace_norm
diff --git a/docs/states.rst b/docs/states.rst
index 68d08d145..a6cfad08e 100644
--- a/docs/states.rst
+++ b/docs/states.rst
@@ -24,7 +24,6 @@ Distance Metrics for Quantum States
     toqito.state_metrics.hilbert_schmidt_inner_product
     toqito.state_metrics.sub_fidelity
     toqito.state_metrics.trace_distance
-    toqito.state_metrics.trace_norm
     toqito.state_metrics.bures_distance
     toqito.state_metrics.matsumoto_fidelity
 
diff --git a/tests/test_state_metrics/test_trace_norm.py b/tests/test_matrix_props/test_trace_norm.py
similarity index 92%
rename from tests/test_state_metrics/test_trace_norm.py
rename to tests/test_matrix_props/test_trace_norm.py
index 1b272a748..ac2d6e138 100644
--- a/tests/test_state_metrics/test_trace_norm.py
+++ b/tests/test_matrix_props/test_trace_norm.py
@@ -1,7 +1,7 @@
 """Tests for trace_norm."""
 import numpy as np
 
-from toqito.state_metrics import trace_norm
+from toqito.matrix_props import trace_norm
 from toqito.states import basis
 
 
diff --git a/toqito/channel_metrics/completely_bounded_trace_norm.py b/toqito/channel_metrics/completely_bounded_trace_norm.py
index 684d44a19..284524c97 100644
--- a/toqito/channel_metrics/completely_bounded_trace_norm.py
+++ b/toqito/channel_metrics/completely_bounded_trace_norm.py
@@ -4,7 +4,7 @@
 
 from toqito.channel_ops import apply_channel, dual_channel
 from toqito.channel_props import is_quantum_channel, is_completely_positive
-from toqito.state_metrics import trace_norm
+from toqito.matrix_props import trace_norm
 
 def completely_bounded_trace_norm(phi: np.ndarray) -> float:
     r"""
diff --git a/toqito/matrix_props/__init__.py b/toqito/matrix_props/__init__.py
index 46be4ec77..682f591cf 100644
--- a/toqito/matrix_props/__init__.py
+++ b/toqito/matrix_props/__init__.py
@@ -16,4 +16,5 @@
 from toqito.matrix_props.majorizes import majorizes
 from toqito.matrix_props.sk_norm import sk_operator_norm
 from toqito.matrix_props.is_block_positive import is_block_positive
-from toqito.matrix_props.is_orthonormal import is_orthonormal
\ No newline at end of file
+from toqito.matrix_props.is_orthonormal import is_orthonormal
+from toqito.matrix_props.trace_norm import trace_norm
\ No newline at end of file
diff --git a/toqito/state_metrics/trace_norm.py b/toqito/matrix_props/trace_norm.py
similarity index 100%
rename from toqito/state_metrics/trace_norm.py
rename to toqito/matrix_props/trace_norm.py
diff --git a/toqito/state_metrics/__init__.py b/toqito/state_metrics/__init__.py
index 6c4df7724..96c8ac6ae 100644
--- a/toqito/state_metrics/__init__.py
+++ b/toqito/state_metrics/__init__.py
@@ -1,5 +1,4 @@
 """Distance metrics for quantum states."""
-from toqito.state_metrics.trace_norm import trace_norm
 from toqito.state_metrics.hilbert_schmidt import hilbert_schmidt
 from toqito.state_metrics.hilbert_schmidt_inner_product import hilbert_schmidt_inner_product
 from toqito.state_metrics.helstrom_holevo import helstrom_holevo
diff --git a/toqito/state_metrics/helstrom_holevo.py b/toqito/state_metrics/helstrom_holevo.py
index 5d62c4ca2..00e72f999 100644
--- a/toqito/state_metrics/helstrom_holevo.py
+++ b/toqito/state_metrics/helstrom_holevo.py
@@ -1,8 +1,7 @@
 """Helstrom-Holevo metric."""
 import numpy as np
 
-from toqito.matrix_props import is_density
-from toqito.state_metrics import trace_norm
+from toqito.matrix_props import is_density, trace_norm
 
 
 def helstrom_holevo(rho: np.ndarray, sigma: np.ndarray) -> float:
diff --git a/toqito/state_metrics/trace_distance.py b/toqito/state_metrics/trace_distance.py
index d8406fb23..1291a0630 100644
--- a/toqito/state_metrics/trace_distance.py
+++ b/toqito/state_metrics/trace_distance.py
@@ -1,8 +1,7 @@
 """Trace distance metric."""
 import numpy as np
 
-from toqito.matrix_props import is_density
-from toqito.state_metrics import trace_norm
+from toqito.matrix_props import is_density, trace_norm
 
 
 def trace_distance(rho: np.ndarray, sigma: np.ndarray) -> float:
diff --git a/toqito/state_props/is_separable.py b/toqito/state_props/is_separable.py
index 3ba126201..69d721414 100644
--- a/toqito/state_props/is_separable.py
+++ b/toqito/state_props/is_separable.py
@@ -4,10 +4,9 @@
 import numpy as np
 
 from toqito.channels import realignment
-from toqito.matrix_props import is_positive_semidefinite
+from toqito.matrix_props import is_positive_semidefinite, trace_norm
 from toqito.state_props import is_ppt, in_separable_ball
 from toqito.state_props.has_symmetric_extension import has_symmetric_extension
-from toqito.state_metrics import trace_norm
 from toqito.perms import swap
 
 from picos import partial_trace