diff --git a/src/main/java/net/fabricmc/loom/decompilers/fernflower/AbstractFernFlowerDecompiler.java b/src/main/java/net/fabricmc/loom/decompilers/fernflower/AbstractFernFlowerDecompiler.java
index ecc1386..fdaa90d 100644
--- a/src/main/java/net/fabricmc/loom/decompilers/fernflower/AbstractFernFlowerDecompiler.java
+++ b/src/main/java/net/fabricmc/loom/decompilers/fernflower/AbstractFernFlowerDecompiler.java
@@ -102,7 +102,7 @@ public abstract class AbstractFernFlowerDecompiler implements LoomDecompiler {
 		ExecResult result = ForkingJavaExec.javaexec(
 				project,
 				spec -> {
-					spec.setMain(fernFlowerExecutor().getName());
+					spec.getMainClass().set(fernFlowerExecutor().getName());
 					spec.jvmArgs("-Xms200m", "-Xmx3G");
 					spec.setArgs(args);
 					spec.setErrorOutput(System.err);