diff --git a/lib/arel/visitors/postgresql.rb b/lib/arel/visitors/postgresql.rb
index 49f7482e7d..60878ddd20 100644
--- a/lib/arel/visitors/postgresql.rb
+++ b/lib/arel/visitors/postgresql.rb
@@ -3,24 +3,25 @@ module Arel
     class PostgreSQL < Arel::Visitors::ToSql
       private
 
-      def visit_Arel_Nodes_Matches o
-        "#{visit o.left} ILIKE #{visit o.right}"
+      def visit_Arel_Nodes_Matches o, collector
+        infix_value o, collector, ' ILIKE '
       end
 
-      def visit_Arel_Nodes_DoesNotMatch o
-        "#{visit o.left} NOT ILIKE #{visit o.right}"
+      def visit_Arel_Nodes_DoesNotMatch o, collector
+        infix_value o, collector, ' NOT ILIKE '
       end
 
-      def visit_Arel_Nodes_Regexp o
-        "#{visit o.left} ~ #{visit o.right}"
+      def visit_Arel_Nodes_Regexp o, collector
+        infix_value o, collector, ' ~ '
       end
 
-      def visit_Arel_Nodes_NotRegexp o
-        "#{visit o.left} !~ #{visit o.right}"
+      def visit_Arel_Nodes_NotRegexp o, collector
+        infix_value o, collector, ' !~ '
       end
 
-      def visit_Arel_Nodes_DistinctOn o
-        "DISTINCT ON ( #{visit o.expr} )"
+      def visit_Arel_Nodes_DistinctOn o, collector
+        collector << "DISTINCT ON ( "
+        visit(o.expr, collector) << " )"
       end
     end
   end
diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb
index 0dbec61212..8e254d504b 100644
--- a/lib/arel/visitors/to_sql.rb
+++ b/lib/arel/visitors/to_sql.rb
@@ -275,8 +275,8 @@ module Arel
         visit o.expr
       end
 
-      def visit_Arel_Nodes_Distinct o
-        DISTINCT
+      def visit_Arel_Nodes_Distinct o, collector
+        collector << DISTINCT
       end
 
       def visit_Arel_Nodes_DistinctOn o, collector
diff --git a/test/visitors/test_postgres.rb b/test/visitors/test_postgres.rb
index 995e9bf515..3d646a7324 100644
--- a/test/visitors/test_postgres.rb
+++ b/test/visitors/test_postgres.rb
@@ -9,16 +9,20 @@ module Arel
         @attr = @table[:id]
       end
 
+      def compile node
+        @visitor.accept(node, Collectors::SQLString.new).value
+      end
+
       describe 'locking' do
         it 'defaults to FOR UPDATE' do
-          @visitor.accept(Nodes::Lock.new(Arel.sql('FOR UPDATE'))).must_be_like %{
+          compile(Nodes::Lock.new(Arel.sql('FOR UPDATE'))).must_be_like %{
             FOR UPDATE
           }
         end
 
         it 'allows a custom string to be used as a lock' do
           node = Nodes::Lock.new(Arel.sql('FOR SHARE'))
-          @visitor.accept(node).must_be_like %{
+          compile(node).must_be_like %{
             FOR SHARE
           }
         end
@@ -29,7 +33,7 @@ module Arel
         sc.limit = Nodes::Limit.new(Nodes.build_quoted("omg"))
         sc.cores.first.projections << Arel.sql('DISTINCT ON')
         sc.orders << Arel.sql("xyz")
-        sql =  @visitor.accept(sc)
+        sql =  compile(sc)
         assert_match(/LIMIT 'omg'/, sql)
         assert_equal 1, sql.scan(/LIMIT/).length, 'should have one limit'
       end
@@ -37,19 +41,19 @@ module Arel
       it 'should support DISTINCT ON' do
         core = Arel::Nodes::SelectCore.new
         core.set_quantifier = Arel::Nodes::DistinctOn.new(Arel.sql('aaron'))
-        assert_match 'DISTINCT ON ( aaron )', @visitor.accept(core)
+        assert_match 'DISTINCT ON ( aaron )', compile(core)
       end
 
       it 'should support DISTINCT' do
         core = Arel::Nodes::SelectCore.new
         core.set_quantifier = Arel::Nodes::Distinct.new
-        assert_equal 'SELECT DISTINCT', @visitor.accept(core)
+        assert_equal 'SELECT DISTINCT', compile(core)
       end
 
       describe "Nodes::Matches" do
         it "should know how to visit" do
           node = @table[:name].matches('foo%')
-          @visitor.accept(node).must_be_like %{
+          compile(node).must_be_like %{
             "users"."name" ILIKE 'foo%'
           }
         end
@@ -57,7 +61,7 @@ module Arel
         it 'can handle subqueries' do
           subquery = @table.project(:id).where(@table[:name].matches('foo%'))
           node = @attr.in subquery
-          @visitor.accept(node).must_be_like %{
+          compile(node).must_be_like %{
             "users"."id" IN (SELECT id FROM "users" WHERE "users"."name" ILIKE 'foo%')
           }
         end
@@ -66,7 +70,7 @@ module Arel
       describe "Nodes::DoesNotMatch" do
         it "should know how to visit" do
           node = @table[:name].does_not_match('foo%')
-          @visitor.accept(node).must_be_like %{
+          compile(node).must_be_like %{
             "users"."name" NOT ILIKE 'foo%'
           }
         end
@@ -74,7 +78,7 @@ module Arel
         it 'can handle subqueries' do
           subquery = @table.project(:id).where(@table[:name].does_not_match('foo%'))
           node = @attr.in subquery
-          @visitor.accept(node).must_be_like %{
+          compile(node).must_be_like %{
             "users"."id" IN (SELECT id FROM "users" WHERE "users"."name" NOT ILIKE 'foo%')
           }
         end
@@ -83,7 +87,7 @@ module Arel
       describe "Nodes::Regexp" do
         it "should know how to visit" do
           node = Arel::Nodes::Regexp.new(@table[:name], Nodes.build_quoted('foo%'))
-          @visitor.accept(node).must_be_like %{
+          compile(node).must_be_like %{
             "users"."name" ~ 'foo%'
           }
         end
@@ -91,7 +95,7 @@ module Arel
         it 'can handle subqueries' do
           subquery = @table.project(:id).where(Arel::Nodes::Regexp.new(@table[:name], Nodes.build_quoted('foo%')))
           node = @attr.in subquery
-          @visitor.accept(node).must_be_like %{
+          compile(node).must_be_like %{
             "users"."id" IN (SELECT id FROM "users" WHERE "users"."name" ~ 'foo%')
           }
         end
@@ -100,7 +104,7 @@ module Arel
       describe "Nodes::NotRegexp" do
         it "should know how to visit" do
           node = Arel::Nodes::NotRegexp.new(@table[:name], Nodes.build_quoted('foo%'))
-          @visitor.accept(node).must_be_like %{
+          compile(node).must_be_like %{
             "users"."name" !~ 'foo%'
           }
         end
@@ -108,7 +112,7 @@ module Arel
         it 'can handle subqueries' do
           subquery = @table.project(:id).where(Arel::Nodes::NotRegexp.new(@table[:name], Nodes.build_quoted('foo%')))
           node = @attr.in subquery
-          @visitor.accept(node).must_be_like %{
+          compile(node).must_be_like %{
             "users"."id" IN (SELECT id FROM "users" WHERE "users"."name" !~ 'foo%')
           }
         end
diff --git a/test/visitors/test_to_sql.rb b/test/visitors/test_to_sql.rb
index 4ed1f225ce..eb102c1905 100644
--- a/test/visitors/test_to_sql.rb
+++ b/test/visitors/test_to_sql.rb
@@ -6,7 +6,6 @@ module Arel
       before do
         @conn = FakeRecord::Base.new
         @visitor = ToSql.new @conn.connection
-        @collector = Collectors::SQLString.new
         @table = Table.new(:users)
         @attr = @table[:id]
       end
@@ -33,7 +32,7 @@ module Arel
           end
         }.new
 
-        viz.accept(@table, @collector)
+        viz.accept(@table, Collectors::SQLString.new)
         assert visited, 'hello method was called'
       end