diff --git a/tabellio/searchform/simple.py b/tabellio/searchform/simple.py
index 4ab12dc..3f1da94 100644
--- a/tabellio/searchform/simple.py
+++ b/tabellio/searchform/simple.py
@@ -25,6 +25,8 @@ class SearchForm(form.Form):
     def deputy_results(self):
         catalog = getToolByName(self.context, 'portal_catalog')
         data, errors = self.extractData()
+        if data.get('SearchableText') is None:
+            return []
         return catalog(
                 portal_type=['themis.datatypes.deputy'],
                 SearchableText=data.get('SearchableText'))
@@ -32,6 +34,8 @@ class SearchForm(form.Form):
     def page_results(self):
         catalog = getToolByName(self.context, 'portal_catalog')
         data, errors = self.extractData()
+        if data.get('SearchableText') is None:
+            return []
         return catalog(
                 portal_type=['Document', 'File', 'Folder', 'Link'],
                 SearchableText=data.get('SearchableText'))
@@ -39,6 +43,8 @@ class SearchForm(form.Form):
     def doc_results(self):
         catalog = getToolByName(self.context, 'portal_catalog')
         data, errors = self.extractData()
+        if data.get('SearchableText') is None:
+            return []
         return catalog(
                 portal_type=['tabellio.documents.dossier', 'tabellio.documents.document'],
                 SearchableText=data.get('SearchableText'))
@@ -46,6 +52,8 @@ class SearchForm(form.Form):
     def event_results(self):
         catalog = getToolByName(self.context, 'portal_catalog')
         data, errors = self.extractData()
+        if data.get('SearchableText') is None:
+            return []
         return catalog(
                 portal_type=['tabellio.agenda.parlevent', 'tabellio.agenda.event'],
                 SearchableText=data.get('SearchableText'))