diff --git a/lib/lol_dba/index_finding/index_finder.rb b/lib/lol_dba/index_finding/index_finder.rb
index a9c9f78..669f249 100644
--- a/lib/lol_dba/index_finding/index_finder.rb
+++ b/lib/lol_dba/index_finding/index_finder.rb
@@ -58,7 +58,12 @@ def self.existing_indexes(table_name)
     def self.table_indexes(table_name)
       indexes = ActiveRecord::Base.connection.indexes(table_name.to_sym)
       indexes.collect do |index|
-        index.columns.size > 1 ? index.columns.sort : index.columns.first
+        if index.columns.is_a?(String)
+          # eg. gin, tsvector...
+          index.columns
+        else
+          index.columns.size > 1 ? index.columns.sort : index.columns.first
+        end
       end
     end