diff --git a/java/preprocessor/build.gradle.kts b/java/preprocessor/build.gradle.kts
index 2af56fd2a..595071e60 100644
--- a/java/preprocessor/build.gradle.kts
+++ b/java/preprocessor/build.gradle.kts
@@ -60,4 +60,7 @@ mavenPublishing{
             developerConnection.set("scm:git:ssh://git@github.com/processing/processing4.git")
         }
     }
+}
+tasks.withType<Jar> {
+    duplicatesStrategy = DuplicatesStrategy.EXCLUDE
 }
\ No newline at end of file