diff --git a/bin/pycbc_make_sky_grid b/bin/pycbc_make_sky_grid
index e59e6fc9f4f..663de80a43a 100644
--- a/bin/pycbc_make_sky_grid
+++ b/bin/pycbc_make_sky_grid
@@ -18,7 +18,6 @@ from scipy.spatial.transform import Rotation as R
 
 import pycbc
 from pycbc.detector import Detector
-from pycbc.io.hdf import HFile
 from pycbc.types import angle_as_radians
 from pycbc.tmpltbank import sky_grid
 
diff --git a/pycbc/tmpltbank/sky_grid.py b/pycbc/tmpltbank/sky_grid.py
index 31b9fe9bdd6..224a585a883 100644
--- a/pycbc/tmpltbank/sky_grid.py
+++ b/pycbc/tmpltbank/sky_grid.py
@@ -8,7 +8,7 @@
 import h5py
 
 from pycbc.detector import Detector
-
+from pycbc.conversion import ensurearray
 
 class SkyGrid:
     def __init__(self, ra, dec, detectors, ref_gps_time):
@@ -34,9 +34,10 @@ def __init__(self, ra, dec, detectors, ref_gps_time):
         # We store the points in a 2D array internally, first dimension runs
         # over the list of points, second dimension is RA/dec.
         # Question: should we use Astropy sky positions instead?
-        if (self.ra < 0).any() or (self.ra > 2 * np.pi).any():
+        ra, dec, _ = ensurearray(ra,dec)
+        if (ra < 0).any() or (ra > 2 * np.pi).any():
             raise ValueError('RA must be in the range [0,2π]')
-        if (self.dec < -np.pi/2).any() or (ra > np.pi/2).any():
+        if (dec < -np.pi/2).any() or (dec > np.pi/2).any():
             raise ValueError('DEC must be in the range [-π/2, π/2]')
         self.positions = np.vstack([ra, dec]).T
         self.detectors = sorted(detectors)