diff --git a/lib/redmine/sort_criteria.rb b/lib/redmine/sort_criteria.rb
index 2a6969486..c89ef03c1 100644
--- a/lib/redmine/sort_criteria.rb
+++ b/lib/redmine/sort_criteria.rb
@@ -87,6 +87,7 @@ module Redmine
     private
 
     def normalize!
+      self.reject! {|s| s.first.blank? }
       self.collect! {|s| s = Array(s); [s.first, (s.last == false || s.last.to_s == 'desc') ? 'desc' : 'asc']}
       self.replace self.first(3)
     end
diff --git a/test/unit/query_test.rb b/test/unit/query_test.rb
index 1a66bc4db..e868ef456 100644
--- a/test/unit/query_test.rb
+++ b/test/unit/query_test.rb
@@ -1496,6 +1496,12 @@ class QueryTest < ActiveSupport::TestCase
     assert_equal [['priority', 'desc'], ['tracker', 'asc'], ['priority', 'asc']], q.sort_criteria
   end
 
+  def test_sort_criteria_should_remove_blank_keys
+    q = IssueQuery.new
+    q.sort_criteria = [['priority', 'desc'], [nil, 'desc'], ['', 'asc'], ['project', 'asc']]
+    assert_equal [['priority', 'desc'], ['project', 'asc']], q.sort_criteria
+  end
+
   def test_set_sort_criteria_with_hash
     q = IssueQuery.new
     q.sort_criteria = {'0' => ['priority', 'desc'], '2' => ['tracker']}