2 files changed, 5 insertions, 3 deletions
diff --git a/lib/arel/nodes/unqualified_column.rb b/lib/arel/nodes/unqualified_column.rb
index b86b553074..31561fddd4 100644
--- a/lib/arel/nodes/unqualified_column.rb
+++ b/lib/arel/nodes/unqualified_column.rb
@@ -5,6 +5,10 @@ module Arel
         @attribute = attribute
       end
 
+      def column
+        @attribute.column
+      end
+
       def name
         @attribute.name
       end
diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb
index 710b6143ec..2ccc9d7d3f 100644
--- a/lib/arel/visitors/to_sql.rb
+++ b/lib/arel/visitors/to_sql.rb
@@ -179,9 +179,7 @@ module Arel
       end
 
       def visit_Arel_Nodes_Assignment o
-        right = o.right
-
-        right = right.nil? ? 'NULL' : visit(right)
+        right = quote(o.right, o.left.column)
         "#{visit o.left} = #{right}"
       end