diff --git a/sapl/sessao/forms.py b/sapl/sessao/forms.py
index 9d4a7c0d3..656a0e1cc 100644
--- a/sapl/sessao/forms.py
+++ b/sapl/sessao/forms.py
@@ -159,6 +159,9 @@ class ExpedienteMateriaForm(ModelForm):
     def clean(self):
         super(ExpedienteMateriaForm, self).clean()
 
+        if self.errors:
+            return self.errors
+
         cleaned_data = self.cleaned_data
         sessao = self.instance.sessao_plenaria