diff --git a/app/controllers/app.js b/app/controllers/app.js
index 8b96f4c29..4a2ebe180 100755
--- a/app/controllers/app.js
+++ b/app/controllers/app.js
@@ -488,7 +488,7 @@ function handleQuery(req, res) {
                 }
 
                 // Only set an X-Cache-Channel for responses we want Varnish to cache.
-                if ( tableCacheItem && ! tableCacheItem.may_write ) {
+                if ( tableCacheItem && tableCacheItem.affected_tables.length > 0 && !tableCacheItem.may_write ) {
                   res.header('X-Cache-Channel', generateCacheKey(dbopts.dbname, tableCacheItem, authenticated));
                 }
 
diff --git a/test/acceptance/app.test.js b/test/acceptance/app.test.js
index 78644c90c..6db04df34 100644
--- a/test/acceptance/app.test.js
+++ b/test/acceptance/app.test.js
@@ -1082,7 +1082,7 @@ it('numeric arrays are rendered as such', function(done){
         assert.equal(out.rows[0].x.length, 2);
         assert.equal(out.rows[0].x[0], '8.7');
         assert.equal(out.rows[0].x[1], '4.3');
-        assert.equal(res.headers['x-cache-channel'], 'cartodb_test_user_1_db:'); // keep forever
+        assert.equal(res.headers.hasOwnProperty('x-cache-channel'), false);
         done();
     });
 });
diff --git a/test/acceptance/x-cache-channel.js b/test/acceptance/x-cache-channel.js
index ea35fb7fa..53c58cc16 100644
--- a/test/acceptance/x-cache-channel.js
+++ b/test/acceptance/x-cache-channel.js
@@ -8,98 +8,106 @@ var _ = require('underscore');
 // allow lots of emitters to be set to silence warning
 app.setMaxListeners(0);
 
-describe('x_cache_channel', function() {
+describe('X-Cache-Channel header', function() {
 
-assert.contains = function(ary, elem) {
-  assert.ok(_.contains(ary,elem), 'missing "' + elem +'" from x-cache-channel: '+ ary);
-};
+    function createGetRequest(sqlQuery) {
+        var query = querystring.stringify({
+            q: sqlQuery,
+            api_key: 1234
+        });
+        return {
+            url: '/api/v1/sql?' + query,
+            headers: {
+                host: 'vizzuality.cartodb.com'
+            },
+            method: 'GET'
+        };
+    }
 
-it('supports joins', function(done) {
-    var query = querystring.stringify({
-       q: "SELECT a.name as an, b.name as bn FROM untitle_table_4 a " +
-           "left join private_table b ON (a.cartodb_id = b.cartodb_id)",
-       api_key: 1234
-    });
-    assert.response(app, {
-        url: '/api/v1/sql?' + query,
-        headers: {host: 'vizzuality.cartodb.com' },
-        method: 'GET'
-    },{ }, function(res) {
-        assert.equal(res.statusCode, 200, res.body);
-        // Check x-cache headers
-        var cc = res.headers['x-cache-channel'].split(':');
-        assert.equal(cc[0], 'cartodb_test_user_1_db');
-        var tt = cc[1].split(',');
-        assert.equal(tt.length, 2);
-        assert.contains(tt, 'public.private_table');
-        assert.contains(tt, 'public.untitle_table_4');
-        done();
+    var RESPONSE_OK = {
+        statusCode: 200
+    };
+
+    function xCacheChannelHeaderHasTables(xCacheChannel, expectedTablesNames) {
+        var databaseAndTables = xCacheChannel.split(':');
+        var databaseName = databaseAndTables[0];
+
+        assert.equal(databaseName, 'cartodb_test_user_1_db');
+
+        var headerTableNames = databaseAndTables[1].split(',');
+        assert.equal(headerTableNames.length, expectedTablesNames.length);
+
+        var tablesDiff = _.difference(expectedTablesNames, headerTableNames);
+        assert.equal(tablesDiff.length, 0, 'X-Cache-Channel header missing tables: ' + tablesDiff.join(','));
+    }
+
+    function tableNamesInCacheChannelHeader(expectedTableNames, done) {
+        return function(res) {
+            xCacheChannelHeaderHasTables(res.headers['x-cache-channel'], expectedTableNames);
+            done();
+        };
+    }
+
+    it('supports joins', function(done) {
+        var sql = "SELECT a.name as an, b.name as bn FROM untitle_table_4 a " +
+            "left join private_table b ON (a.cartodb_id = b.cartodb_id)";
+
+        assert.response(app, createGetRequest(sql), RESPONSE_OK, tableNamesInCacheChannelHeader([
+            'public.private_table',
+            'public.untitle_table_4'
+        ], done));
     });
-});
 
-it('supports multistatements', function(done) {
-    var query = querystring.stringify({
-       q: "SELECT * FROM untitle_table_4; SELECT * FROM private_table",
-       api_key: 1234
+    it('supports multistatements', function(done) {
+        var sql = "SELECT * FROM untitle_table_4; SELECT * FROM private_table";
+
+        assert.response(app, createGetRequest(sql), RESPONSE_OK, tableNamesInCacheChannelHeader([
+            'public.private_table',
+            'public.untitle_table_4'
+        ], done));
     });
-    assert.response(app, {
-        url: '/api/v1/sql?' + query,
-        headers: {host: 'vizzuality.cartodb.com' },
-        method: 'GET'
-    },{ }, function(res) {
-        assert.equal(res.statusCode, 200, res.body);
-        // Check x-cache headers
-        var cc = res.headers['x-cache-channel'].split(':');
-        assert.equal(cc[0], 'cartodb_test_user_1_db');
-        var tt = cc[1].split(',');
-        assert.equal(tt.length, 2);
-        assert.contains(tt, 'public.private_table');
-        assert.contains(tt, 'public.untitle_table_4');
-        done();
+
+    it('supports explicit transactions', function(done) {
+        var sql =  "BEGIN; SELECT * FROM untitle_table_4; COMMIT; BEGIN; SELECT * FROM private_table; COMMIT;";
+
+        assert.response(app, createGetRequest(sql), RESPONSE_OK, tableNamesInCacheChannelHeader([
+            'public.private_table',
+            'public.untitle_table_4'
+        ], done));
     });
-});
 
-it('supports explicit transactions', function(done) {
-    var query = querystring.stringify({
-       q: "BEGIN; SELECT * FROM untitle_table_4; COMMIT; BEGIN; SELECT * FROM private_table; COMMIT;",
-       api_key: 1234
+    it('survives partial transactions', function(done) {
+        var sql = "BEGIN; SELECT * FROM untitle_table_4";
+
+        assert.response(app, createGetRequest(sql), RESPONSE_OK, tableNamesInCacheChannelHeader([
+            'public.untitle_table_4'
+        ], done));
     });
-    assert.response(app, {
-        url: '/api/v1/sql?' + query,
-        headers: {host: 'vizzuality.cartodb.com' },
-        method: 'GET'
-    },{ }, function(res) {
-        assert.equal(res.statusCode, 200, res.body);
-        // Check x-cache headers
-        var cc = res.headers['x-cache-channel'].split(':');
-        assert.equal(cc[0], 'cartodb_test_user_1_db');
-        var tt = cc[1].split(',');
-        assert.equal(tt.length, 2);
-        assert.contains(tt, 'public.private_table');
-        assert.contains(tt, 'public.untitle_table_4');
-        done();
+
+    it('should not add header for functions', function(done) {
+        var sql = "SELECT format('%s', 'wadus')";
+        assert.response(app, createGetRequest(sql), RESPONSE_OK, function(res) {
+            assert.ok(!res.headers.hasOwnProperty('x-cache-channel'), res.headers['x-cache-channel']);
+            done();
+        });
     });
-});
 
-it('survives partial transactions', function(done) {
-    var query = querystring.stringify({
-       q: "BEGIN; SELECT * FROM untitle_table_4",
-       api_key: 1234
+    it('should not add header for CDB_QueryTables', function(done) {
+        var sql = "SELECT CDB_QueryTablesText('select * from untitle_table_4')";
+        assert.response(app, createGetRequest(sql), RESPONSE_OK, function(res) {
+            assert.ok(!res.headers.hasOwnProperty('x-cache-channel'), res.headers['x-cache-channel']);
+            done();
+        });
     });
-    assert.response(app, {
-        url: '/api/v1/sql?' + query,
-        headers: {host: 'vizzuality.cartodb.com' },
-        method: 'GET'
-    },{ }, function(res) {
-        assert.equal(res.statusCode, 200, res.body);
-        // Check x-cache headers
-        var cc = res.headers['x-cache-channel'].split(':');
-        assert.equal(cc[0], 'cartodb_test_user_1_db');
-        var tt = cc[1].split(',');
-        assert.equal(tt.length, 1);
-        assert.contains(tt, 'public.untitle_table_4');
-        done();
+
+    it('should not add header for non table results', function(done) {
+        var sql = "SELECT 'wadus'::text";
+        assert.response(app, createGetRequest(sql), RESPONSE_OK, function(res) {
+            assert.ok(!res.headers.hasOwnProperty('x-cache-channel'), res.headers['x-cache-channel']);
+            done();
+        });
     });
-});
+
+
 
 });