diff --git a/core/src/main/java/org/jruby/RubyClass.java b/core/src/main/java/org/jruby/RubyClass.java
index 1cfa35594e3..19e51dc5185 100644
--- a/core/src/main/java/org/jruby/RubyClass.java
+++ b/core/src/main/java/org/jruby/RubyClass.java
@@ -1009,15 +1009,6 @@ public IRubyObject initialize_copy(IRubyObject original) {
         return this;
     }
 
-    protected void setModuleSuperClass(RubyClass superClass) {
-        // remove us from old superclass's child classes
-        if (this.superClass != null) this.superClass.removeSubclass(this);
-        // add us to new superclass's child classes
-        superClass.addSubclass(this);
-        // update superclass reference
-        setSuperClass(superClass);
-    }
-
     @JRubyMethod
     public IRubyObject subclasses(ThreadContext context) {
         int subclassEstimate = this.subclassEstimate;