diff --git a/src/py21cmsense/observatory.py b/src/py21cmsense/observatory.py
index ca3a053..96519b3 100644
--- a/src/py21cmsense/observatory.py
+++ b/src/py21cmsense/observatory.py
@@ -245,8 +245,8 @@ def from_ska(
             from ska_ost_array_config.array_config import LowSubArray, MidSubArray
         except ImportError:
             raise ImportError(
-                "ska-ost-array-config package is required, "+
-                "see https://gitlab.com/ska-telescope/ost/ska-ost-array-config"
+                "ska-ost-array-config package is required, "
+                + "see https://gitlab.com/ska-telescope/ost/ska-ost-array-config"
             )
         if array_type == "low":
             subarray = LowSubArray(subarray_type, **kwargs)
diff --git a/tests/test_observatory.py b/tests/test_observatory.py
index 8f949be..f2a01fc 100644
--- a/tests/test_observatory.py
+++ b/tests/test_observatory.py
@@ -206,9 +206,10 @@ def test_from_yaml(bm):
 
 
 def test_from_ska():
-    Observatory.from_ska(subarray_type="AA*", array_type="low", frequency=300.*units.MHz)
-    Observatory.from_ska(subarray_type="AA*", array_type="mid", frequency=300.*units.MHz)
-    Observatory.from_ska(subarray_type="AA4", array_type="low", frequency=300.*units.MHz)
+    Observatory.from_ska(subarray_type="AA*", array_type="low", frequency=300.0 * units.MHz)
+    Observatory.from_ska(subarray_type="AA*", array_type="mid", frequency=300.0 * units.MHz)
+    Observatory.from_ska(subarray_type="AA4", array_type="low", frequency=300.0 * units.MHz)
+
 
 def test_get_redundant_baselines(bm):
     a = Observatory(antpos=np.array([[0, 0, 0], [1, 0, 0], [2, 0, 0]]) * units.m, beam=bm)