diff --git a/zoidberg/poloidal_grid.py b/zoidberg/poloidal_grid.py
index 76db8c0..8b525ea 100644
--- a/zoidberg/poloidal_grid.py
+++ b/zoidberg/poloidal_grid.py
@@ -294,7 +294,7 @@ def __init__(self, R, Z):
 
         xinds = np.arange(nx)
         zinds = np.arange(nz * 3)
-        # Repeat the final point in y since periodic in y
+        # Repeat the data in z, to approximate periodicity
         R_ext = np.concatenate((R, R, R), axis=1)
         Z_ext = np.concatenate((Z, Z, Z), axis=1)