diff --git a/tests/form_pages/test_block.py b/tests/form_pages/test_block.py
index d770f30d0..9a541cdbe 100644
--- a/tests/form_pages/test_block.py
+++ b/tests/form_pages/test_block.py
@@ -707,12 +707,13 @@ def test_block_repeated_files(pub, blocks_feature):
     assert 'test2.txt' in resp
 
 
-def test_block_digest(pub, blocks_feature):
+@pytest.mark.parametrize('block_name', ['foobar', 'Foo bar'])
+def test_block_digest(pub, blocks_feature, block_name):
     FormDef.wipe()
     BlockDef.wipe()
 
     block = BlockDef()
-    block.name = 'foobar'
+    block.name = block_name
     block.fields = [
         fields.StringField(
             id='123', required=True, label='Test',
@@ -726,7 +727,7 @@ def test_block_digest(pub, blocks_feature):
     formdef = FormDef()
     formdef.name = 'form title'
     formdef.fields = [
-        fields.BlockField(id='1', label='test', type='block:foobar', max_items=3),
+        fields.BlockField(id='1', label='test', type='block:%s' % block.slug, max_items=3),
     ]
     formdef.store()
     formdef.data_class().wipe()
@@ -745,12 +746,12 @@ def test_block_digest(pub, blocks_feature):
     assert formdef.data_class().select()[0].data['1']['data'] == [
             {'123': 'foo', '234': 'bar'}, {'123': 'foo2', '234': 'bar2'}]
     # by default it gets the type of object
-    assert formdef.data_class().select()[0].data['1_display'] == 'foobar, foobar'
+    assert formdef.data_class().select()[0].data['1_display'] == '%s, %s' % (block.name, block.name)
 
     # set a digest template
     formdef.data_class().wipe()
 
-    block.digest_template = 'X{{foobar_var_foo}}Y'
+    block.digest_template = 'X{{%s_var_foo}}Y' % block.slug.replace('-', '_')
     block.store()
 
     resp = app.get(formdef.get_url())
diff --git a/wcs/admin/blocks.py b/wcs/admin/blocks.py
index 010d28d0c..06619bfe1 100644
--- a/wcs/admin/blocks.py
+++ b/wcs/admin/blocks.py
@@ -147,7 +147,9 @@ class BlockDirectory(FieldsDirectory):
         if disabled_slug:
             widget.hint = _('The identifier can not be modified as the block is in use.')
         form.add(
-            StringWidget, 'digest_template', title=_('Digest Template'), value=self.objectdef.digest_template, size=50
+            StringWidget, 'digest_template', title=_('Digest Template'),
+            value=self.objectdef.digest_template, size=50,
+            hint=_('Use %s_var_... to refer to fields.') % self.objectdef.slug.replace('-', '_')
         )
         if not self.objectdef.is_readonly():
             form.add_submit('submit', _('Submit'))
@@ -164,7 +166,7 @@ class BlockDirectory(FieldsDirectory):
             if widget_template.parse() and 'form_var_' in widget_template.parse():
                 widget_template.set_error(
                     _('Wrong variable "form_var_…" detected. Please replace it by "%s_var_…".')
-                    % self.objectdef.slug)
+                    % self.objectdef.slug.replace('-', '_'))
             else:
                 self.objectdef.digest_template = widget_template.parse()
                 self.objectdef.store()
diff --git a/wcs/blocks.py b/wcs/blocks.py
index e8623076f..8a599da7f 100644
--- a/wcs/blocks.py
+++ b/wcs/blocks.py
@@ -92,7 +92,8 @@ class BlockDef(StorableObject):
         from .qommon.substitution import CompatibilityNamesDict
         from .variables import LazyBlockDataVar
 
-        context = CompatibilityNamesDict({self.slug + '_var': LazyBlockDataVar(self.fields, value)})
+        context = CompatibilityNamesDict(
+                {self.slug.replace('-', '_') + '_var': LazyBlockDataVar(self.fields, value)})
         return Template(self.digest_template, autoescape=False).render(context)
 
     def export_to_xml(self, include_id=False):