diff --git a/package/lib/fits.py b/package/lib/fits.py
index 62425f4..43d62d9 100755
--- a/package/lib/fits.py
+++ b/package/lib/fits.py
@@ -213,10 +213,10 @@ def save_Stokes(
         [P, "Pol_deg"],
         [debiased_P, "Pol_deg_debiased"],
         [s_P, "Pol_deg_err"],
-        [s_P_P, "Pol_deg_err_Poisson_noise"],
+        [s_P_P, "Pol_deg_stat_err"],
         [PA, "Pol_ang"],
         [s_PA, "Pol_ang_err"],
-        [s_PA_P, "Pol_ang_err_Poisson_noise"],
+        [s_PA_P, "Pol_ang_stat_err"],
         [data_mask, "Data_mask"],
     ]:
         hdu_header = header.copy()
diff --git a/package/lib/plots.py b/package/lib/plots.py
index e428d28..2dfdb28 100755
--- a/package/lib/plots.py
+++ b/package/lib/plots.py
@@ -2978,7 +2978,7 @@ class pol_map(object):
         return self.Stokes["DATA_MASK"].data
 
     def set_data_mask(self, mask):
-        self.Stokes[np.argmax([self.Stokes[i].header["datatype"] == "Data_mask" for i in range(len(self.Stokes))])].data = mask.astype(float)
+        self.Stokes["DATA_MASK"].data = mask.astype(float)
 
     @property
     def cut(self):