diff --git a/include/swift/Demangling/Demangle.h b/include/swift/Demangling/Demangle.h
index 95e3c21662bbc..edb6591c708e2 100644
--- a/include/swift/Demangling/Demangle.h
+++ b/include/swift/Demangling/Demangle.h
@@ -949,7 +949,7 @@ class NodePrinter {
 
   void printImplFunctionType(NodePointer fn, unsigned depth);
 
-  void printGenericSignature(NodePointer Node, unsigned depth);
+  virtual void printGenericSignature(NodePointer Node, unsigned depth);
 
   void printFunctionSigSpecializationParams(NodePointer Node, unsigned depth);