diff --git a/src/main/java/groovy/lang/GroovyClassLoader.java b/src/main/java/groovy/lang/GroovyClassLoader.java
index 360c9b92e71..4f95301c454 100644
--- a/src/main/java/groovy/lang/GroovyClassLoader.java
+++ b/src/main/java/groovy/lang/GroovyClassLoader.java
@@ -104,6 +104,10 @@ public class GroovyClassLoader extends URLClassLoader {
     private final String sourceEncoding;
     private Boolean recompile;
 
+    static {
+        registerAsParallelCapable();
+    }
+
     /**
      * Creates a GroovyClassLoader using the current Thread's context ClassLoader as parent.
      */