diff --git a/.github/workflows/test-package.yml b/.github/workflows/test-package.yml
index 00de485a..0a1da86b 100644
--- a/.github/workflows/test-package.yml
+++ b/.github/workflows/test-package.yml
@@ -58,4 +58,5 @@ jobs:
         with:
           run: |
             export NAVIS_HEADLESS=TRUE
+            export NAVIS_TEST_ENV=TRUE
             pytest --verbose
diff --git a/navis/morpho/mmetrics.py b/navis/morpho/mmetrics.py
index 93a4feca..d7986791 100644
--- a/navis/morpho/mmetrics.py
+++ b/navis/morpho/mmetrics.py
@@ -15,6 +15,7 @@
 """This module contains functions to analyse and manipulate neuron morphology."""
 
 import math
+import os
 import itertools
 import scipy
 import warnings
@@ -30,6 +31,12 @@
 # Set up logging
 logger = config.get_logger(__name__)
 
+# Set up numpy number representation, see NEP51
+# Once numpy<=2 is dropped from requirements, the doctest comparissons
+# should become `np.float64(1.074)` instead of `1.074`
+if os.environ.get('NAVIS_TEST_ENV', '').lower() == 'true':
+    np.set_printoptions(legacy="1.25")
+
 __all__ = sorted(
     [
         "strahler_index",
@@ -1321,12 +1328,7 @@ def tortuosity(
 
     Examples
     --------
-    (Set up numpy number representation within the test, see NEP51.
-    Once numpy<=2 is dropped from requirements, the doctest comparissons
-    should become `np.float64(1.074)` instead of `1.074`)
     >>> import navis
-    >>> if int(np.version.version.split('.')[0])>=2:
-        np.set_printoptions(legacy="1.25")
     >>> n = navis.example_neurons(1)
     >>> # Calculate tortuosity as-is
     >>> T = navis.tortuosity(n)
diff --git a/pytest.ini b/pytest.ini
index 6754b78f..f7278cac 100644
--- a/pytest.ini
+++ b/pytest.ini
@@ -3,3 +3,4 @@ doctest_optionflags = IGNORE_EXCEPTION_DETAIL NUMBER NORMALIZE_WHITESPACE
 addopts = --doctest-modules
 env =
     NAVIS_HEADLESS=TRUE
+    NAVIS_TEST_ENV=TRUE