diff --git a/src/Kaleidoscope/HostOS-Base.h b/src/Kaleidoscope/HostOS-Base.h
index c3bce54e..b0a2f562 100644
--- a/src/Kaleidoscope/HostOS-Base.h
+++ b/src/Kaleidoscope/HostOS-Base.h
@@ -33,7 +33,7 @@ typedef enum {
 
 class Base : public KaleidoscopePlugin {
  public:
-  virtual void begin(void) final;
+  void begin(void) final;
 
   Type os(void);
   void os(Type osType);