diff --git a/src/btop.cpp b/src/btop.cpp
index e59ba4f..893b013 100644
--- a/src/btop.cpp
+++ b/src/btop.cpp
@@ -391,8 +391,8 @@ namespace Runner {
 	class MyNumPunct : public std::numpunct<char>
 	{
 	protected:
-		virtual char do_thousands_sep() const { return '\''; }
-		virtual std::string do_grouping() const { return "\03"; }
+		virtual char do_thousands_sep() const override { return '\''; }
+		virtual std::string do_grouping() const override { return "\03"; }
 	};
 
 
diff --git a/src/btop_tools.hpp b/src/btop_tools.hpp
index 30a2780..45da4e0 100644
--- a/src/btop_tools.hpp
+++ b/src/btop_tools.hpp
@@ -190,8 +190,8 @@ namespace Tools {
 
 	class MyNumPunct : public std::numpunct<char> {
 	protected:
-		virtual char do_thousands_sep() const { return '\''; }
-		virtual std::string do_grouping() const { return "\03"; }
+		virtual char do_thousands_sep() const override { return '\''; }
+		virtual std::string do_grouping() const override { return "\03"; }
 	};
 
 	size_t wide_ulen(const string& str);