diff --git a/nipype/interfaces/mrtrix3/tests/test_auto_TensorMetrics.py b/nipype/interfaces/mrtrix3/tests/test_auto_TensorMetrics.py
index bbe12033cb..28c33b0796 100644
--- a/nipype/interfaces/mrtrix3/tests/test_auto_TensorMetrics.py
+++ b/nipype/interfaces/mrtrix3/tests/test_auto_TensorMetrics.py
@@ -7,6 +7,9 @@ def test_TensorMetrics_inputs():
         args=dict(
             argstr="%s",
         ),
+        bval_scale=dict(
+            argstr="-bvalue_scaling %s",
+        ),
         component=dict(
             argstr="-num %s",
             sep=",",
@@ -16,6 +19,22 @@ def test_TensorMetrics_inputs():
             nohash=True,
             usedefault=True,
         ),
+        grad_file=dict(
+            argstr="-grad %s",
+            extensions=None,
+            xor=["grad_fsl"],
+        ),
+        grad_fsl=dict(
+            argstr="-fslgrad %s %s",
+            xor=["grad_file"],
+        ),
+        in_bval=dict(
+            extensions=None,
+        ),
+        in_bvec=dict(
+            argstr="-fslgrad %s %s",
+            extensions=None,
+        ),
         in_file=dict(
             argstr="%s",
             extensions=None,
@@ -29,6 +48,10 @@ def test_TensorMetrics_inputs():
         modulate=dict(
             argstr="-modulate %s",
         ),
+        nthreads=dict(
+            argstr="-nthreads %d",
+            nohash=True,
+        ),
         out_ad=dict(
             argstr="-ad %s",
             extensions=None,
@@ -37,6 +60,13 @@ def test_TensorMetrics_inputs():
             argstr="-adc %s",
             extensions=None,
         ),
+        out_bval=dict(
+            extensions=None,
+        ),
+        out_bvec=dict(
+            argstr="-export_grad_fsl %s %s",
+            extensions=None,
+        ),
         out_cl=dict(
             argstr="-cl %s",
             extensions=None,
diff --git a/nipype/interfaces/mrtrix3/utils.py b/nipype/interfaces/mrtrix3/utils.py
index 8a69232ecd..1a7c81dada 100644
--- a/nipype/interfaces/mrtrix3/utils.py
+++ b/nipype/interfaces/mrtrix3/utils.py
@@ -318,7 +318,7 @@ def _list_outputs(self):
         return outputs
 
 
-class TensorMetricsInputSpec(CommandLineInputSpec):
+class TensorMetricsInputSpec(MRTrix3BaseInputSpec):
     in_file = File(
         exists=True,
         argstr="%s",