diff --git a/src/colvarbias_meta.h b/src/colvarbias_meta.h
index 59ce6a83f..0e20b625b 100644
--- a/src/colvarbias_meta.h
+++ b/src/colvarbias_meta.h
@@ -55,10 +55,11 @@ class colvarbias_meta
   virtual int calc_energy(std::vector<colvarvalue> const *values);
   virtual int calc_forces(std::vector<colvarvalue> const *values);
 
-  virtual std::string const get_state_params() const;
-  virtual int set_state_params(std::string const &state_conf);
-  virtual std::ostream & write_state_data(std::ostream &os);
-  virtual std::istream & read_state_data(std::istream &os);
+  std::string const get_state_params() const override;
+  int set_state_params(std::string const &state_conf) override;
+
+  std::ostream &write_state_data(std::ostream &os) override;
+  std::istream &read_state_data(std::istream &is) override;
 
   virtual int setup_output();
   virtual int write_output_files();