diff --git a/pyuvdata/utils.py b/pyuvdata/utils.py
index 89058042c5..944af495a2 100644
--- a/pyuvdata/utils.py
+++ b/pyuvdata/utils.py
@@ -6044,11 +6044,7 @@ def determine_rectangularity(
         baseline_array = baseline_array.reshape((nbls, ntimes))
         if np.sum(np.abs(np.diff(time_array, axis=0))) != 0:
             return False, False
-        if np.any(
-            np.logical_not(
-                np.apply_along_axis(lambda x: np.allclose(x, x[0]), 1, baseline_array)
-            )
-        ):
+        if (np.diff(baseline_array, axis=1) != 0).any():
             return False, False
         return True, True
     elif bl_first:
@@ -6056,10 +6052,6 @@ def determine_rectangularity(
         baseline_array = baseline_array.reshape((ntimes, nbls))
         if np.sum(np.abs(np.diff(time_array, axis=1))) != 0:
             return False, False
-        if np.any(
-            np.logical_not(
-                np.apply_along_axis(lambda x: np.allclose(x, x[0]), 0, baseline_array)
-            )
-        ):
+        if (np.diff(baseline_array, axis=0) != 0).any():
             return False, False
         return True, False