diff --git a/ippisite/ippidb/forms.py b/ippisite/ippidb/forms.py
index 44d7f4df7c1d8a50cbda956beb5bbc82804f6110..b5a9d495f224ecddee885c8103f66c23a58c147c 100644
--- a/ippisite/ippidb/forms.py
+++ b/ippisite/ippidb/forms.py
@@ -254,7 +254,7 @@ class ComplexCompositionForm(forms.Form):
         queryset=Domain.objects.none(),
         required=False,
         widget=forms.Select(attrs={'class': 'form-control'}),
-        empty_label="Unidentified",
+        empty_label="Unknown",
     )
     ppc_copy_nb = forms.IntegerField(
         label="Number of copies of the protein in the complex",