diff --git a/wagtail/wagtailadmin/templatetags/wagtailadmin_tags.py b/wagtail/wagtailadmin/templatetags/wagtailadmin_tags.py
index be4d67425..3a4a21d41 100644
--- a/wagtail/wagtailadmin/templatetags/wagtailadmin_tags.py
+++ b/wagtail/wagtailadmin/templatetags/wagtailadmin_tags.py
@@ -46,7 +46,7 @@ def main_nav_js():
 def ellipsistrim(value, max_length):
     if len(value) > max_length:
         truncd_val = value[:max_length]
-        if not len(value) == max_length+1 and value[max_length+1] != " ":
+        if not len(value) == (max_length + 1) and value[max_length + 1] != " ":
             truncd_val = truncd_val[:truncd_val.rfind(" ")]
         return truncd_val + "..."
     return value
diff --git a/wagtail/wagtailimages/views/multiple.py b/wagtail/wagtailimages/views/multiple.py
index eb67dacee..428a7f49e 100644
--- a/wagtail/wagtailimages/views/multiple.py
+++ b/wagtail/wagtailimages/views/multiple.py
@@ -111,7 +111,7 @@ def edit(request, image_id, callback=None):
     if not image.is_editable_by_user(request.user):
         raise PermissionDenied
 
-    form = ImageForm(request.POST, request.FILES, instance=image, prefix='image-'+image_id)
+    form = ImageForm(request.POST, request.FILES, instance=image, prefix='image-' + image_id)
 
     if form.is_valid():
         form.save()