diff --git a/arduino-core/src/cc/arduino/packages/Uploader.java b/arduino-core/src/cc/arduino/packages/Uploader.java
index 1d1967c36..cd9a11a45 100644
--- a/arduino-core/src/cc/arduino/packages/Uploader.java
+++ b/arduino-core/src/cc/arduino/packages/Uploader.java
@@ -134,7 +134,11 @@ public abstract class Uploader implements MessageConsumer {
       if (!process.waitFor(2, TimeUnit.MINUTES)) {
         process.destroyForcibly();
       }
-      result = process.exitValue();
+      if (!process.isAlive()) {
+        result = process.exitValue();
+      } else {
+        result = 0;
+      }
     } catch (Exception e) {
       e.printStackTrace();
     }
diff --git a/arduino-core/src/processing/app/Platform.java b/arduino-core/src/processing/app/Platform.java
index b999c8264..0c2c1d8cb 100644
--- a/arduino-core/src/processing/app/Platform.java
+++ b/arduino-core/src/processing/app/Platform.java
@@ -181,7 +181,7 @@ public class Platform {
     return list;
   }
 
-  public Map<String, Object> resolveDeviceByVendorIdProductId(String serial, Map<String, TargetPackage> packages) {
+  public synchronized Map<String, Object> resolveDeviceByVendorIdProductId(String serial, Map<String, TargetPackage> packages) {
     String vid_pid_iSerial = resolveDeviceAttachedToNative(serial);
     for (TargetPackage targetPackage : packages.values()) {
       for (TargetPlatform targetPlatform : targetPackage.getPlatforms().values()) {