diff --git a/pymaster/workspaces.py b/pymaster/workspaces.py
index b5d7c4ac..8eb43a51 100644
--- a/pymaster/workspaces.py
+++ b/pymaster/workspaces.py
@@ -485,7 +485,7 @@ def purify_if_needed(fld, mp):
                 for m in range(f1.nmaps)])
             # SHT^-1[C^ab*SHT[w*gj]]
             gtild_j = ut.alm2map(gtild_j, f1.spin, f1.wt.minfo,
-                                 f1.ainfo) * f1.mask[None, :]
+                                 f1.ainfo)
             if f1.n_temp > 0:
                 # Int[f^i*v*SHT^-1[C^ab*SHT[w*gj]]]
                 for ii, ti in enumerate(f1.temp):