diff --git a/.github/workflows/ant.yml b/.github/workflows/ant.yml
index a0a91efa9e1..11b9bd1a5ee 100644
--- a/.github/workflows/ant.yml
+++ b/.github/workflows/ant.yml
@@ -1,6 +1,8 @@
 name: Java CI
 
-on: [push]
+on:
+  push:
+  pull_request:
 
 jobs:
   build:
diff --git a/app/test/cc/arduino/contributions/GzippedJsonDownloaderTest.java b/app/test/cc/arduino/contributions/GzippedJsonDownloaderTest.java
index 745ccb1dd5b..f57700c621b 100644
--- a/app/test/cc/arduino/contributions/GzippedJsonDownloaderTest.java
+++ b/app/test/cc/arduino/contributions/GzippedJsonDownloaderTest.java
@@ -8,6 +8,8 @@
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
+
+import processing.app.BaseNoGui;
 import processing.app.helpers.FileUtils;
 
 import java.io.File;
@@ -38,6 +40,7 @@ public void tearDown() throws Exception {
 
   @Test
   public void testJsonDownload() throws Exception {
+    BaseNoGui.initPlatform();
     new GZippedJsonDownloader(downloader, new URL("http://downloads.arduino.cc/libraries/library_index.json"),
       new URL("http://downloads.arduino.cc/libraries/library_index.json.gz"))
       .download(tempFile, new MultiStepProgress(1), "", new NoopProgressListener(), true);
diff --git a/app/test/cc/arduino/contributions/JsonDownloaderTest.java b/app/test/cc/arduino/contributions/JsonDownloaderTest.java
index bdb64325f59..98555be4d60 100644
--- a/app/test/cc/arduino/contributions/JsonDownloaderTest.java
+++ b/app/test/cc/arduino/contributions/JsonDownloaderTest.java
@@ -8,6 +8,8 @@
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
+
+import processing.app.BaseNoGui;
 import processing.app.helpers.FileUtils;
 
 import java.io.File;
@@ -38,6 +40,7 @@ public void tearDown() throws Exception {
 
   @Test
   public void testJsonDownload() throws Exception {
+    BaseNoGui.initPlatform();
     new JsonDownloader(downloader, new URL("http://downloads.arduino.cc/libraries/library_index.json"))
       .download(tempFile, new MultiStepProgress(1), "", new NoopProgressListener(), true);
 
diff --git a/arduino-core/src/processing/app/BaseNoGui.java b/arduino-core/src/processing/app/BaseNoGui.java
index 59ef009a60b..bd7f672925e 100644
--- a/arduino-core/src/processing/app/BaseNoGui.java
+++ b/arduino-core/src/processing/app/BaseNoGui.java
@@ -509,7 +509,7 @@ static public void initPackages() throws Exception {
     }
   }
 
-  static protected void initPlatform() {
+  static public void initPlatform() {
     try {
       Class<?> platformClass = Class.forName("processing.app.Platform");
       if (OSUtils.isMacOS()) {