diff --git a/src/COMPRESS/dump_atom_gz.h b/src/COMPRESS/dump_atom_gz.h
index 2b87e36f1d..b7cd1bf476 100644
--- a/src/COMPRESS/dump_atom_gz.h
+++ b/src/COMPRESS/dump_atom_gz.h
@@ -28,17 +28,16 @@ namespace LAMMPS_NS {
 class DumpAtomGZ : public DumpAtom {
  public:
   DumpAtomGZ(class LAMMPS *, int, char **);
-  virtual ~DumpAtomGZ() = default;
 
  protected:
   GzFileWriter writer;
 
-  virtual void openfile();
-  virtual void write_header(bigint);
-  virtual void write_data(int, double *);
-  virtual void write();
+  void openfile() override;
+  void write_header(bigint) override;
+  void write_data(int, double *) override;
+  void write() override;
 
-  virtual int modify_param(int, char **);
+  int modify_param(int, char **) override;
 };
 
 }    // namespace LAMMPS_NS
diff --git a/src/COMPRESS/dump_atom_zstd.h b/src/COMPRESS/dump_atom_zstd.h
index fb2da0c83b..9bc9796915 100644
--- a/src/COMPRESS/dump_atom_zstd.h
+++ b/src/COMPRESS/dump_atom_zstd.h
@@ -34,17 +34,16 @@ namespace LAMMPS_NS {
 class DumpAtomZstd : public DumpAtom {
  public:
   DumpAtomZstd(class LAMMPS *, int, char **);
-  virtual ~DumpAtomZstd() = default;
 
  protected:
   ZstdFileWriter writer;
 
-  virtual void openfile();
-  virtual void write_header(bigint);
-  virtual void write_data(int, double *);
-  virtual void write();
+  void openfile() override;
+  void write_header(bigint) override;
+  void write_data(int, double *) override;
+  void write() override;
 
-  virtual int modify_param(int, char **);
+  int modify_param(int, char **) override;
 };
 
 }    // namespace LAMMPS_NS
diff --git a/src/COMPRESS/dump_cfg_gz.h b/src/COMPRESS/dump_cfg_gz.h
index 153a4490c6..ca88600b51 100644
--- a/src/COMPRESS/dump_cfg_gz.h
+++ b/src/COMPRESS/dump_cfg_gz.h
@@ -28,17 +28,16 @@ namespace LAMMPS_NS {
 class DumpCFGGZ : public DumpCFG {
  public:
   DumpCFGGZ(class LAMMPS *, int, char **);
-  virtual ~DumpCFGGZ() = default;
 
  protected:
   GzFileWriter writer;
 
-  virtual void openfile();
-  virtual void write_header(bigint);
-  virtual void write_data(int, double *);
-  virtual void write();
+  void openfile() override;
+  void write_header(bigint) override;
+  void write_data(int, double *) override;
+  void write() override;
 
-  virtual int modify_param(int, char **);
+  int modify_param(int, char **) override;
 };
 
 }    // namespace LAMMPS_NS
diff --git a/src/COMPRESS/dump_cfg_zstd.h b/src/COMPRESS/dump_cfg_zstd.h
index 32013b274e..88541503f8 100644
--- a/src/COMPRESS/dump_cfg_zstd.h
+++ b/src/COMPRESS/dump_cfg_zstd.h
@@ -33,17 +33,16 @@ namespace LAMMPS_NS {
 class DumpCFGZstd : public DumpCFG {
  public:
   DumpCFGZstd(class LAMMPS *, int, char **);
-  virtual ~DumpCFGZstd() = default;
 
  protected:
   ZstdFileWriter writer;
 
-  virtual void openfile();
-  virtual void write_header(bigint);
-  virtual void write_data(int, double *);
-  virtual void write();
+  void openfile() override;
+  void write_header(bigint) override;
+  void write_data(int, double *) override;
+  void write() override;
 
-  virtual int modify_param(int, char **);
+  int modify_param(int, char **) override;
 };
 
 }    // namespace LAMMPS_NS
diff --git a/src/COMPRESS/dump_custom_gz.h b/src/COMPRESS/dump_custom_gz.h
index 660af8bfae..ba0a1a83fc 100644
--- a/src/COMPRESS/dump_custom_gz.h
+++ b/src/COMPRESS/dump_custom_gz.h
@@ -28,17 +28,16 @@ namespace LAMMPS_NS {
 class DumpCustomGZ : public DumpCustom {
  public:
   DumpCustomGZ(class LAMMPS *, int, char **);
-  virtual ~DumpCustomGZ() = default;
 
  protected:
   GzFileWriter writer;
 
-  virtual void openfile();
-  virtual void write_header(bigint);
-  virtual void write_data(int, double *);
-  virtual void write();
+  void openfile() override;
+  void write_header(bigint) override;
+  void write_data(int, double *) override;
+  void write() override;
 
-  virtual int modify_param(int, char **);
+  int modify_param(int, char **) override;
 };
 
 }    // namespace LAMMPS_NS
diff --git a/src/COMPRESS/dump_custom_zstd.h b/src/COMPRESS/dump_custom_zstd.h
index f179223265..d9b836c365 100644
--- a/src/COMPRESS/dump_custom_zstd.h
+++ b/src/COMPRESS/dump_custom_zstd.h
@@ -34,17 +34,16 @@ namespace LAMMPS_NS {
 class DumpCustomZstd : public DumpCustom {
  public:
   DumpCustomZstd(class LAMMPS *, int, char **);
-  virtual ~DumpCustomZstd() = default;
 
  protected:
   ZstdFileWriter writer;
 
-  virtual void openfile();
-  virtual void write_header(bigint);
-  virtual void write_data(int, double *);
-  virtual void write();
+  void openfile() override;
+  void write_header(bigint) override;
+  void write_data(int, double *) override;
+  void write() override;
 
-  virtual int modify_param(int, char **);
+  int modify_param(int, char **) override;
 };
 
 }    // namespace LAMMPS_NS
diff --git a/src/COMPRESS/dump_local_gz.h b/src/COMPRESS/dump_local_gz.h
index e2e7a028aa..b2e2c55127 100644
--- a/src/COMPRESS/dump_local_gz.h
+++ b/src/COMPRESS/dump_local_gz.h
@@ -28,17 +28,16 @@ namespace LAMMPS_NS {
 class DumpLocalGZ : public DumpLocal {
  public:
   DumpLocalGZ(class LAMMPS *, int, char **);
-  virtual ~DumpLocalGZ() = default;
 
  protected:
   GzFileWriter writer;
 
-  virtual void openfile();
-  virtual void write_header(bigint);
-  virtual void write_data(int, double *);
-  virtual void write();
+  void openfile() override;
+  void write_header(bigint) override;
+  void write_data(int, double *) override;
+  void write() override;
 
-  virtual int modify_param(int, char **);
+  int modify_param(int, char **) override;
 };
 
 }    // namespace LAMMPS_NS
diff --git a/src/COMPRESS/dump_local_zstd.h b/src/COMPRESS/dump_local_zstd.h
index fb4f017b3d..cc04c6512a 100644
--- a/src/COMPRESS/dump_local_zstd.h
+++ b/src/COMPRESS/dump_local_zstd.h
@@ -34,17 +34,16 @@ namespace LAMMPS_NS {
 class DumpLocalZstd : public DumpLocal {
  public:
   DumpLocalZstd(class LAMMPS *, int, char **);
-  virtual ~DumpLocalZstd() = default;
 
  protected:
   ZstdFileWriter writer;
 
-  virtual void openfile();
-  virtual void write_header(bigint);
-  virtual void write_data(int, double *);
-  virtual void write();
+  void openfile() override;
+  void write_header(bigint) override;
+  void write_data(int, double *) override;
+  void write() override;
 
-  virtual int modify_param(int, char **);
+  int modify_param(int, char **) override;
 };
 
 }    // namespace LAMMPS_NS
diff --git a/src/COMPRESS/dump_xyz_gz.h b/src/COMPRESS/dump_xyz_gz.h
index 62a25cfc66..714911c735 100644
--- a/src/COMPRESS/dump_xyz_gz.h
+++ b/src/COMPRESS/dump_xyz_gz.h
@@ -28,17 +28,16 @@ namespace LAMMPS_NS {
 class DumpXYZGZ : public DumpXYZ {
  public:
   DumpXYZGZ(class LAMMPS *, int, char **);
-  virtual ~DumpXYZGZ() = default;
 
  protected:
   GzFileWriter writer;
 
-  virtual void openfile();
-  virtual void write_header(bigint);
-  virtual void write_data(int, double *);
-  virtual void write();
+  void openfile() override;
+  void write_header(bigint) override;
+  void write_data(int, double *) override;
+  void write() override;
 
-  virtual int modify_param(int, char **);
+  int modify_param(int, char **) override;
 };
 
 }    // namespace LAMMPS_NS
diff --git a/src/COMPRESS/dump_xyz_zstd.h b/src/COMPRESS/dump_xyz_zstd.h
index 110e27ab8f..fe93be1156 100644
--- a/src/COMPRESS/dump_xyz_zstd.h
+++ b/src/COMPRESS/dump_xyz_zstd.h
@@ -34,17 +34,16 @@ namespace LAMMPS_NS {
 class DumpXYZZstd : public DumpXYZ {
  public:
   DumpXYZZstd(class LAMMPS *, int, char **);
-  virtual ~DumpXYZZstd() = default;
 
  protected:
   ZstdFileWriter writer;
 
-  virtual void openfile();
-  virtual void write_header(bigint);
-  virtual void write_data(int, double *);
-  virtual void write();
+  void openfile() override;
+  void write_header(bigint) override;
+  void write_data(int, double *) override;
+  void write() override;
 
-  virtual int modify_param(int, char **);
+  int modify_param(int, char **) override;
 };
 
 }    // namespace LAMMPS_NS
diff --git a/src/COMPRESS/gz_file_writer.h b/src/COMPRESS/gz_file_writer.h
index 3de1d0d2b8..2356675921 100644
--- a/src/COMPRESS/gz_file_writer.h
+++ b/src/COMPRESS/gz_file_writer.h
@@ -31,12 +31,12 @@ class GzFileWriter : public FileWriter {
   gzFile gzFp;    // file pointer for the compressed output stream
  public:
   GzFileWriter();
-  virtual ~GzFileWriter();
-  virtual void open(const std::string &path, bool append = false) override;
-  virtual void close() override;
-  virtual void flush() override;
-  virtual size_t write(const void *buffer, size_t length) override;
-  virtual bool isopen() const override;
+  ~GzFileWriter() override;
+  void open(const std::string &path, bool append = false) override;
+  void close() override;
+  void flush() override;
+  size_t write(const void *buffer, size_t length) override;
+  bool isopen() const override;
 
   void setCompressionLevel(int level);
 };
diff --git a/src/COMPRESS/zstd_file_writer.h b/src/COMPRESS/zstd_file_writer.h
index 3fde376b47..77b3838f83 100644
--- a/src/COMPRESS/zstd_file_writer.h
+++ b/src/COMPRESS/zstd_file_writer.h
@@ -42,12 +42,12 @@ class ZstdFileWriter : public FileWriter {
 
  public:
   ZstdFileWriter();
-  virtual ~ZstdFileWriter();
-  virtual void open(const std::string &path, bool append = false) override;
-  virtual void close() override;
-  virtual void flush() override;
-  virtual size_t write(const void *buffer, size_t length) override;
-  virtual bool isopen() const override;
+  ~ZstdFileWriter() override;
+  void open(const std::string &path, bool append = false) override;
+  void close() override;
+  void flush() override;
+  size_t write(const void *buffer, size_t length) override;
+  bool isopen() const override;
 
   void setCompressionLevel(int level);
   void setChecksum(bool enabled);
diff --git a/src/EXTRA-DUMP/dump_dcd.h b/src/EXTRA-DUMP/dump_dcd.h
index b445742104..e6e7e3c766 100644
--- a/src/EXTRA-DUMP/dump_dcd.h
+++ b/src/EXTRA-DUMP/dump_dcd.h
@@ -27,7 +27,7 @@ namespace LAMMPS_NS {
 class DumpDCD : public Dump {
  public:
   DumpDCD(LAMMPS *, int, char **);
-  virtual ~DumpDCD();
+  ~DumpDCD() override;
 
  private:
   int natoms, ntotal;
@@ -36,13 +36,13 @@ class DumpDCD : public Dump {
   float *coords, *xf, *yf, *zf;
   int unwrap_flag;    // 1 if atom coords are unwrapped, 0 if no
 
-  void init_style();
-  void openfile();
-  void write_header(bigint);
-  void pack(tagint *);
-  void write_data(int, double *);
-  int modify_param(int, char **);
-  double memory_usage();
+  void init_style() override;
+  void openfile() override;
+  void write_header(bigint) override;
+  void pack(tagint *) override;
+  void write_data(int, double *) override;
+  int modify_param(int, char **) override;
+  double memory_usage() override;
 
   void write_frame();
   void write_dcd_header(const char *);
diff --git a/src/EXTRA-DUMP/dump_xtc.h b/src/EXTRA-DUMP/dump_xtc.h
index ef26b70295..4fd5ee57ff 100644
--- a/src/EXTRA-DUMP/dump_xtc.h
+++ b/src/EXTRA-DUMP/dump_xtc.h
@@ -28,7 +28,7 @@ namespace LAMMPS_NS {
 class DumpXTC : public Dump {
  public:
   DumpXTC(class LAMMPS *, int, char **);
-  virtual ~DumpXTC();
+  ~DumpXTC() override;
 
  private:
   int natoms, ntotal;
@@ -39,13 +39,13 @@ class DumpXTC : public Dump {
   double sfactor, tfactor;    // scaling factors for positions and time unit
   XDR xd;
 
-  void init_style();
-  int modify_param(int, char **);
-  void openfile();
-  void write_header(bigint);
-  void pack(tagint *);
-  void write_data(int, double *);
-  double memory_usage();
+  void init_style() override;
+  int modify_param(int, char **) override;
+  void openfile() override;
+  void write_header(bigint) override;
+  void pack(tagint *) override;
+  void write_data(int, double *) override;
+  double memory_usage() override;
 
   void write_frame();
 };
diff --git a/src/MOLFILE/dump_molfile.h b/src/MOLFILE/dump_molfile.h
index 968ed783ca..3f627835e6 100644
--- a/src/MOLFILE/dump_molfile.h
+++ b/src/MOLFILE/dump_molfile.h
@@ -29,8 +29,8 @@ namespace LAMMPS_NS {
 class DumpMolfile : public Dump {
  public:
   DumpMolfile(LAMMPS *, int, char **);
-  virtual ~DumpMolfile();
-  virtual void write();
+  ~DumpMolfile() override;
+  void write() override;
 
  protected:
   class MolfileInterface *mf;    //< handles low-level I/O
@@ -46,13 +46,13 @@ class DumpMolfile : public Dump {
   int topology_flag;    // 1 if writing topology data, 0 if not
   float cell[6];        // cell parameters: A, B, C, alpha, beta, gamma
 
-  virtual void init_style();
-  virtual int modify_param(int, char **);
-  virtual void write_header(bigint){};
-  virtual void pack(tagint *);
-  virtual void write_data(int, double *);
-  virtual double memory_usage();
-  virtual void openfile();
+  void init_style() override;
+  int modify_param(int, char **) override;
+  void write_header(bigint) override{};
+  void pack(tagint *) override;
+  void write_data(int, double *) override;
+  double memory_usage() override;
+  void openfile() override;
 };
 
 }    // namespace LAMMPS_NS
diff --git a/src/UEF/dump_cfg_uef.h b/src/UEF/dump_cfg_uef.h
index 56df6db033..d4fa3bfc02 100644
--- a/src/UEF/dump_cfg_uef.h
+++ b/src/UEF/dump_cfg_uef.h
@@ -29,8 +29,8 @@ namespace LAMMPS_NS {
 class DumpCFGUef : public DumpCFG {
  public:
   DumpCFGUef(LAMMPS *lmp, int narg, char **arg) : DumpCFG(lmp, narg, arg) {}
-  void init_style();
-  void write_header(bigint);
+  void init_style() override;
+  void write_header(bigint) override;
 
  protected:
   int ifix_uef;
diff --git a/src/UEF/fix_nh_uef.h b/src/UEF/fix_nh_uef.h
index b8fb776366..8f74de7bbb 100644
--- a/src/UEF/fix_nh_uef.h
+++ b/src/UEF/fix_nh_uef.h
@@ -27,28 +27,28 @@ namespace UEF_utils {
 class FixNHUef : public FixNH {
  public:
   FixNHUef(class LAMMPS *, int, char **);
-  virtual ~FixNHUef();
-  virtual int setmask();
-  virtual void init();
-  virtual void setup(int);
-  virtual void pre_exchange();
-  virtual int pack_restart_data(double *);
-  virtual void restart(char *);
-  virtual void end_of_step();
-  virtual void initial_integrate(int);
-  virtual void final_integrate();
-  virtual void initial_integrate_respa(int, int, int);
-  virtual void final_integrate_respa(int, int);
-  virtual void post_run();
+  ~FixNHUef() override;
+  int setmask() override;
+  void init() override;
+  void setup(int) override;
+  void pre_exchange() override;
+  int pack_restart_data(double *) override;
+  void restart(char *) override;
+  void end_of_step() override;
+  void initial_integrate(int) override;
+  void final_integrate() override;
+  void initial_integrate_respa(int, int, int) override;
+  void final_integrate_respa(int, int) override;
+  void post_run() override;
   void get_rot(double[3][3]);
   void get_ext_flags(bool *);
   void get_box(double[3][3]);
 
  protected:
-  virtual void remap();
-  virtual int size_restart_global();
-  virtual void nve_x();
-  virtual void nve_v();
+  void remap() override;
+  int size_restart_global() override;
+  void nve_x() override;
+  void nve_v() override;
   void rotate_x(double[3][3]);
   void inv_rotate_x(double[3][3]);
   void rotate_v(double[3][3]);
diff --git a/src/dump.h b/src/dump.h
index 35da154d7c..b18b7293c0 100644
--- a/src/dump.h
+++ b/src/dump.h
@@ -37,7 +37,7 @@ class Dump : protected Pointers {
 #endif
 
   Dump(class LAMMPS *, int, char **);
-  virtual ~Dump();
+  ~Dump() override;
   void init();
   virtual void write();
 
diff --git a/src/dump_atom.h b/src/dump_atom.h
index b960bf3665..1e1a9315d7 100644
--- a/src/dump_atom.h
+++ b/src/dump_atom.h
@@ -38,12 +38,12 @@ class DumpAtom : public Dump {
 
   char *columns;    // column labels
 
-  void init_style();
-  int modify_param(int, char **);
-  void write_header(bigint);
-  void pack(tagint *);
-  int convert_string(int, double *);
-  void write_data(int, double *);
+  void init_style() override;
+  int modify_param(int, char **) override;
+  void write_header(bigint) override;
+  void pack(tagint *) override;
+  int convert_string(int, double *) override;
+  void write_data(int, double *) override;
 
   void header_format_binary();
   void header_unit_style_binary();
diff --git a/src/dump_cfg.h b/src/dump_cfg.h
index 49699a2789..21b5396677 100644
--- a/src/dump_cfg.h
+++ b/src/dump_cfg.h
@@ -29,16 +29,16 @@ class DumpCFG : public DumpCustom {
   int multifile_override;    // used by write_dump command
 
   DumpCFG(class LAMMPS *, int, char **);
-  virtual ~DumpCFG();
+  ~DumpCFG() override;
 
  protected:
   char **auxname;    // name strings of auxiliary properties
   int unwrapflag;    // 1 if unwrapped coordinates are requested
 
-  void init_style();
-  virtual void write_header(bigint);
-  int convert_string(int, double *);
-  virtual void write_data(int, double *);
+  void init_style() override;
+  void write_header(bigint) override;
+  int convert_string(int, double *) override;
+  void write_data(int, double *) override;
 
   typedef void (DumpCFG::*FnPtrWrite)(int, double *);
   FnPtrWrite write_choice;    // ptr to write data functions
diff --git a/src/dump_custom.h b/src/dump_custom.h
index 4209d8e46f..5a99cca009 100644
--- a/src/dump_custom.h
+++ b/src/dump_custom.h
@@ -27,7 +27,7 @@ namespace LAMMPS_NS {
 class DumpCustom : public Dump {
  public:
   DumpCustom(class LAMMPS *, int, char **);
-  virtual ~DumpCustom();
+  ~DumpCustom() override;
 
   const char *MAGIC_STRING = "DUMPCUSTOM";
   const int FORMAT_REVISION = 0x0002;
@@ -97,20 +97,20 @@ class DumpCustom : public Dump {
 
   // private methods
 
-  virtual void init_style();
-  virtual void write_header(bigint);
-  int count();
-  void pack(tagint *);
-  virtual int convert_string(int, double *);
-  virtual void write_data(int, double *);
-  double memory_usage();
+  void init_style() override;
+  void write_header(bigint) override;
+  int count() override;
+  void pack(tagint *) override;
+  int convert_string(int, double *) override;
+  void write_data(int, double *) override;
+  double memory_usage() override;
 
   int parse_fields(int, char **);
   int add_compute(const char *);
   int add_fix(const char *);
   int add_variable(const char *);
   int add_custom(const char *, int);
-  virtual int modify_param(int, char **);
+  int modify_param(int, char **) override;
 
   void header_format_binary();
   void header_unit_style_binary();
diff --git a/src/dump_deprecated.h b/src/dump_deprecated.h
index 811fde2edb..3e51f19dda 100644
--- a/src/dump_deprecated.h
+++ b/src/dump_deprecated.h
@@ -28,11 +28,11 @@ namespace LAMMPS_NS {
 class DumpDeprecated : public Dump {
  public:
   DumpDeprecated(class LAMMPS *, int, char **);
-  ~DumpDeprecated() {}
-  virtual void init_style() {}
-  virtual void write_header(bigint) {}
-  virtual void pack(tagint *) {}
-  virtual void write_data(int, double *) {}
+  ~DumpDeprecated() override {}
+  void init_style() override {}
+  void write_header(bigint) override {}
+  void pack(tagint *) override {}
+  void write_data(int, double *) override {}
 };
 
 }    // namespace LAMMPS_NS
diff --git a/src/dump_image.h b/src/dump_image.h
index e3bf1a9183..6c2f419f2e 100644
--- a/src/dump_image.h
+++ b/src/dump_image.h
@@ -29,9 +29,9 @@ class DumpImage : public DumpCustom {
   int multifile_override;    // used by write_dump command
 
   DumpImage(class LAMMPS *, int, char **);
-  virtual ~DumpImage();
-  int pack_forward_comm(int, int *, double *, int, int *);
-  void unpack_forward_comm(int, int, double *);
+  ~DumpImage() override;
+  int pack_forward_comm(int, int *, double *, int, int *) override;
+  void unpack_forward_comm(int, int, double *) override;
 
  protected:
   int filetype;
@@ -91,9 +91,9 @@ class DumpImage : public DumpCustom {
   double **bufcopy;    // buffer for communicating bond/atom info
   int maxbufcopy;
 
-  virtual void init_style();
-  int modify_param(int, char **);
-  void write();
+  void init_style() override;
+  int modify_param(int, char **) override;
+  void write() override;
 
   void box_center();
   void view_params();
diff --git a/src/dump_local.h b/src/dump_local.h
index 1bbdbb1db7..7cd441c8e7 100644
--- a/src/dump_local.h
+++ b/src/dump_local.h
@@ -27,7 +27,7 @@ namespace LAMMPS_NS {
 class DumpLocal : public Dump {
  public:
   DumpLocal(LAMMPS *, int, char **);
-  virtual ~DumpLocal();
+  ~DumpLocal() override;
 
  protected:
   int nevery;     // dump frequency to check Fix against
@@ -53,13 +53,13 @@ class DumpLocal : public Dump {
   char **id_fix;      // their IDs
   class Fix **fix;    // list of ptrs to the Fix objects
 
-  void init_style();
-  int modify_param(int, char **);
-  virtual void write_header(bigint);
-  int count();
-  void pack(tagint *);
-  int convert_string(int, double *);
-  virtual void write_data(int, double *);
+  void init_style() override;
+  int modify_param(int, char **) override;
+  void write_header(bigint) override;
+  int count() override;
+  void pack(tagint *) override;
+  int convert_string(int, double *) override;
+  void write_data(int, double *) override;
 
   void parse_fields(int, char **);
   int add_compute(const char *);
diff --git a/src/dump_movie.h b/src/dump_movie.h
index 770193e039..dd302d40b3 100644
--- a/src/dump_movie.h
+++ b/src/dump_movie.h
@@ -27,11 +27,11 @@ namespace LAMMPS_NS {
 class DumpMovie : public DumpImage {
  public:
   DumpMovie(LAMMPS *, int, char **);
-  virtual ~DumpMovie();
+  ~DumpMovie() override;
 
-  virtual void openfile();
-  virtual void init_style();
-  virtual int modify_param(int, char **);
+  void openfile() override;
+  void init_style() override;
+  int modify_param(int, char **) override;
 
  protected:
   double framerate;    // frame rate of animation
diff --git a/src/dump_xyz.h b/src/dump_xyz.h
index b517a1db13..e9d43a5d91 100644
--- a/src/dump_xyz.h
+++ b/src/dump_xyz.h
@@ -27,18 +27,18 @@ namespace LAMMPS_NS {
 class DumpXYZ : public Dump {
  public:
   DumpXYZ(class LAMMPS *, int, char **);
-  virtual ~DumpXYZ();
+  ~DumpXYZ() override;
 
  protected:
   int ntypes;
   char **typenames;
 
-  void init_style();
-  void write_header(bigint);
-  void pack(tagint *);
-  int convert_string(int, double *);
-  void write_data(int, double *);
-  int modify_param(int, char **);
+  void init_style() override;
+  void write_header(bigint) override;
+  void pack(tagint *) override;
+  int convert_string(int, double *) override;
+  void write_data(int, double *) override;
+  int modify_param(int, char **) override;
 
   typedef void (DumpXYZ::*FnPtrWrite)(int, double *);
   FnPtrWrite write_choice;    // ptr to write data functions
diff --git a/src/file_writer.h b/src/file_writer.h
index 42e636d16f..ff54371d2e 100644
--- a/src/file_writer.h
+++ b/src/file_writer.h
@@ -39,9 +39,9 @@ class FileWriterException : public std::exception {
  public:
   FileWriterException(const std::string &msg) : message(msg) {}
 
-  ~FileWriterException() noexcept {}
+  ~FileWriterException() noexcept override {}
 
-  virtual const char *what() const noexcept { return message.c_str(); }
+  const char *what() const noexcept override { return message.c_str(); }
 };
 
 }    // namespace LAMMPS_NS
diff --git a/src/image.h b/src/image.h
index f9937cacfa..9eb5c899cb 100644
--- a/src/image.h
+++ b/src/image.h
@@ -35,7 +35,7 @@ class Image : protected Pointers {
   int background[3];          // RGB values of background
 
   Image(class LAMMPS *, int);
-  ~Image();
+  ~Image() override;
   void buffers();
   void clear();
   void merge();
@@ -150,7 +150,7 @@ class ColorMap : protected Pointers {
   int dynamic;    // 0/1 if lo/hi bounds are static/dynamic
 
   ColorMap(class LAMMPS *, class Image *);
-  ~ColorMap();
+  ~ColorMap() override;
   int reset(int, char **);
   int minmax(double, double);
   double *value2color(double);