diff --git a/xara/kpo.py b/xara/kpo.py
index 548d62a..f39713b 100644
--- a/xara/kpo.py
+++ b/xara/kpo.py
@@ -108,7 +108,7 @@ def __init__(self, fname=None, array=None, ndgt=5, bmax=None, ID=""):
         # covariance?
         # -----------
         try:
-            test = hdul['KP_COV']
+            test = hdul['KP-COV']
             self.kp_cov = test.data
             print("Covariance data available and loaded")
         except KeyError:
@@ -545,7 +545,7 @@ def update_cov_matrix(self, kp_cov=None, phi_cov=None):
         matrix based on an analytical model.
         ------------------------------------------------------------------ '''
         if phi_cov is not None:
-            self.phi_cov = kp_cov
+            self.phi_cov = phi_cov
         else:
             try:
                 _ = self.CVIS[0]