diff --git a/src/glog/logging.h.in b/src/glog/logging.h.in
index 1e552fc1a..de8c9b99c 100644
--- a/src/glog/logging.h.in
+++ b/src/glog/logging.h.in
@@ -1128,7 +1128,7 @@ class GOOGLE_GLOG_DLL_DECL LogStreamBuf : public std::streambuf {
   }
 
   // This effectively ignores overflow.
-  virtual int_type overflow(int_type ch) {
+  virtual int_type overflow(int_type ch) override {
     return ch;
   }