diff --git a/lib/cartodb/api/api-router.js b/lib/cartodb/api/api-router.js
index af82a3b8..c4124ac8 100644
--- a/lib/cartodb/api/api-router.js
+++ b/lib/cartodb/api/api-router.js
@@ -100,7 +100,8 @@ module.exports = class ApiRouter {
 
         const tileBackend = new windshaft.backend.Tile(rendererCache);
         const attributesBackend = new windshaft.backend.Attributes();
-        const previewBackend = new windshaft.backend.Preview(rendererCache);
+        const concurrency = serverOptions.renderer.mapnik.poolSize + serverOptions.renderer.mapnik.poolMaxWaitingClients;
+        const previewBackend = new windshaft.backend.Preview(rendererCache, { concurrency });
         const mapValidatorBackend = new windshaft.backend.MapValidator(tileBackend, attributesBackend);
         const mapBackend = new windshaft.backend.Map(rendererCache, mapStore, mapValidatorBackend);
 
diff --git a/package-lock.json b/package-lock.json
index 498aad19..90ce19a4 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -5,9 +5,8 @@
   "requires": true,
   "dependencies": {
     "@carto/cartonik": {
-      "version": "0.6.1",
-      "resolved": "https://registry.npmjs.org/@carto/cartonik/-/cartonik-0.6.1.tgz",
-      "integrity": "sha512-7tRnEe8JTGzbYxBcsXhneWzK2HVP/Fc4KcI0PNIgMAUsu3q2Yz3tikA9/OoT9PtGvcOmqNn6CwfVibBKwYO23Q==",
+      "version": "github:cartodb/cartonik#c91fa13562a1fbda30d55405e86ed72bae503eda",
+      "from": "github:cartodb/cartonik#19-preview-batch-fetchs",
       "requires": {
         "@carto/mapnik": "3.6.2-carto.16",
         "@mapbox/sphericalmercator": "^1.1.0",
@@ -4040,11 +4039,10 @@
       "integrity": "sha1-tDFbtCFKPXBY6+7okuE/ok2YsHU="
     },
     "windshaft": {
-      "version": "5.5.1",
-      "resolved": "https://registry.npmjs.org/windshaft/-/windshaft-5.5.1.tgz",
-      "integrity": "sha512-Z8ChaxzBThnYCaSQsJJ5uWdNlTQRBndXvefn8DCaU8pikGfG1kcUD6IGE306MziljNDikKJC5XKf5Dmx6Awt5g==",
+      "version": "github:cartodb/windshaft#29b0c44e8d74eec8658460eb16b940f02ee157ec",
+      "from": "github:cartodb/windshaft#update-cartonik-0.7.0",
       "requires": {
-        "@carto/cartonik": "^0.6.1",
+        "@carto/cartonik": "github:cartodb/cartonik#19-preview-batch-fetchs",
         "@carto/mapnik": "3.6.2-carto.16",
         "canvas": "^2.4.1",
         "carto": "github:cartodb/carto#0.15.1-cdb5",
diff --git a/package.json b/package.json
index 0bd04ffe..608f90bf 100644
--- a/package.json
+++ b/package.json
@@ -49,7 +49,7 @@
     "step-profiler": "0.3.0",
     "turbo-carto": "0.21.2",
     "underscore": "1.6.0",
-    "windshaft": "^5.5.1",
+    "windshaft": "github:cartodb/windshaft#update-cartonik-0.7.0",
     "yargs": "11.1.0"
   },
   "devDependencies": {
diff --git a/test/acceptance/ported/support/ported_server_options.js b/test/acceptance/ported/support/ported_server_options.js
index b0fddbe2..cf040a48 100644
--- a/test/acceptance/ported/support/ported_server_options.js
+++ b/test/acceptance/ported/support/ported_server_options.js
@@ -50,6 +50,7 @@ module.exports = _.extend({}, serverOptions, {
     renderer: {
         mapnik: {
             poolSize: 4,//require('os').cpus().length,
+            poolMaxWaitingClients: 32,
             metatile: 1,
             bufferSize: 64,
             snapToGrid: false,