diff --git a/lib/acts_as_faceted.rb b/lib/acts_as_faceted.rb
index 84a5c5a..58f06de 100644
--- a/lib/acts_as_faceted.rb
+++ b/lib/acts_as_faceted.rb
@@ -134,7 +134,11 @@ module ActsAsFaceted
         if facet[:queries_order]
           facets_data
         elsif sort_by == :alphabetically
-          facets_data.sort{ |a,b| a[1] <=> b[1] }
+          facets_data.sort do |a,b| 
+            a = a[1].is_a?(String) ? a[1] : a.first
+            b = b[1].is_a?(String) ? b[1] : b.first
+            a <=> b
+          end
         elsif sort_by == :count
            facets_data.sort{ |a,b| -1*(a[2] <=> b[2]) }
         else
--
libgit2 0.21.2