diff --git a/submodule.h b/submodule.h
index 4644683e6c..c98cd983e1 100644
--- a/submodule.h
+++ b/submodule.h
@@ -33,62 +33,62 @@ struct submodule_update_strategy {
 };
 #define SUBMODULE_UPDATE_STRATEGY_INIT {SM_UPDATE_UNSPECIFIED, NULL}
 
-extern int is_gitmodules_unmerged(const struct index_state *istate);
-extern int is_staging_gitmodules_ok(struct index_state *istate);
-extern int update_path_in_gitmodules(const char *oldpath, const char *newpath);
-extern int remove_path_from_gitmodules(const char *path);
-extern void stage_updated_gitmodules(struct index_state *istate);
-extern void set_diffopt_flags_from_submodule_config(struct diff_options *,
-		const char *path);
-extern int git_default_submodule_config(const char *var, const char *value, void *cb);
+int is_gitmodules_unmerged(const struct index_state *istate);
+int is_staging_gitmodules_ok(struct index_state *istate);
+int update_path_in_gitmodules(const char *oldpath, const char *newpath);
+int remove_path_from_gitmodules(const char *path);
+void stage_updated_gitmodules(struct index_state *istate);
+void set_diffopt_flags_from_submodule_config(struct diff_options *,
+					     const char *path);
+int git_default_submodule_config(const char *var, const char *value, void *cb);
 
 struct option;
 int option_parse_recurse_submodules_worktree_updater(const struct option *opt,
 						     const char *arg, int unset);
-extern int is_submodule_active(struct repository *repo, const char *path);
+int is_submodule_active(struct repository *repo, const char *path);
 /*
  * Determine if a submodule has been populated at a given 'path' by checking if
  * the <path>/.git resolves to a valid git repository.
  * If return_error_code is NULL, die on error.
  * Otherwise the return error code is the same as of resolve_gitdir_gently.
  */
-extern int is_submodule_populated_gently(const char *path, int *return_error_code);
-extern void die_in_unpopulated_submodule(const struct index_state *istate,
-					 const char *prefix);
-extern void die_path_inside_submodule(const struct index_state *istate,
-				      const struct pathspec *ps);
-extern enum submodule_update_type parse_submodule_update_type(const char *value);
-extern int parse_submodule_update_strategy(const char *value,
-		struct submodule_update_strategy *dst);
-extern const char *submodule_strategy_to_string(const struct submodule_update_strategy *s);
-extern void handle_ignore_submodules_arg(struct diff_options *, const char *);
-extern void show_submodule_summary(struct diff_options *o, const char *path,
-		struct object_id *one, struct object_id *two,
-		unsigned dirty_submodule);
-extern void show_submodule_inline_diff(struct diff_options *o, const char *path,
-		struct object_id *one, struct object_id *two,
-		unsigned dirty_submodule);
+int is_submodule_populated_gently(const char *path, int *return_error_code);
+void die_in_unpopulated_submodule(const struct index_state *istate,
+				  const char *prefix);
+void die_path_inside_submodule(const struct index_state *istate,
+			       const struct pathspec *ps);
+enum submodule_update_type parse_submodule_update_type(const char *value);
+int parse_submodule_update_strategy(const char *value,
+				    struct submodule_update_strategy *dst);
+const char *submodule_strategy_to_string(const struct submodule_update_strategy *s);
+void handle_ignore_submodules_arg(struct diff_options *, const char *);
+void show_submodule_summary(struct diff_options *o, const char *path,
+			    struct object_id *one, struct object_id *two,
+			    unsigned dirty_submodule);
+void show_submodule_inline_diff(struct diff_options *o, const char *path,
+				struct object_id *one, struct object_id *two,
+				unsigned dirty_submodule);
 /* Check if we want to update any submodule.*/
-extern int should_update_submodules(void);
+int should_update_submodules(void);
 /*
  * Returns the submodule struct if the given ce entry is a submodule
  * and it should be updated. Returns NULL otherwise.
  */
-extern const struct submodule *submodule_from_ce(const struct cache_entry *ce);
-extern void check_for_new_submodule_commits(struct object_id *oid);
-extern int fetch_populated_submodules(struct repository *r,
-				      const struct argv_array *options,
-				      const char *prefix,
-				      int command_line_option,
-				      int default_option,
-				      int quiet, int max_parallel_jobs);
-extern unsigned is_submodule_modified(const char *path, int ignore_untracked);
-extern int submodule_uses_gitfile(const char *path);
+const struct submodule *submodule_from_ce(const struct cache_entry *ce);
+void check_for_new_submodule_commits(struct object_id *oid);
+int fetch_populated_submodules(struct repository *r,
+			       const struct argv_array *options,
+			       const char *prefix,
+			       int command_line_option,
+			       int default_option,
+			       int quiet, int max_parallel_jobs);
+unsigned is_submodule_modified(const char *path, int ignore_untracked);
+int submodule_uses_gitfile(const char *path);
 
 #define SUBMODULE_REMOVAL_DIE_ON_ERROR (1<<0)
 #define SUBMODULE_REMOVAL_IGNORE_UNTRACKED (1<<1)
 #define SUBMODULE_REMOVAL_IGNORE_IGNORED_UNTRACKED (1<<2)
-extern int bad_to_remove_submodule(const char *path, unsigned flags);
+int bad_to_remove_submodule(const char *path, unsigned flags);
 
 int add_submodule_odb(const char *path);
 
@@ -96,17 +96,17 @@ int add_submodule_odb(const char *path);
  * Checks if there are submodule changes in a..b. If a is the null OID,
  * checks b and all its ancestors instead.
  */
-extern int submodule_touches_in_range(struct object_id *a,
-				      struct object_id *b);
-extern int find_unpushed_submodules(struct oid_array *commits,
-				    const char *remotes_name,
-				    struct string_list *needs_pushing);
+int submodule_touches_in_range(struct object_id *a,
+			       struct object_id *b);
+int find_unpushed_submodules(struct oid_array *commits,
+			     const char *remotes_name,
+			     struct string_list *needs_pushing);
 struct refspec;
-extern int push_unpushed_submodules(struct oid_array *commits,
-				    const struct remote *remote,
-				    const struct refspec *rs,
-				    const struct string_list *push_options,
-				    int dry_run);
+int push_unpushed_submodules(struct oid_array *commits,
+			     const struct remote *remote,
+			     const struct refspec *rs,
+			     const struct string_list *push_options,
+			     int dry_run);
 /*
  * Given a submodule path (as in the index), return the repository
  * path of that submodule in 'buf'. Return -1 on error or when the
@@ -116,10 +116,10 @@ int submodule_to_gitdir(struct strbuf *buf, const char *submodule);
 
 #define SUBMODULE_MOVE_HEAD_DRY_RUN (1<<0)
 #define SUBMODULE_MOVE_HEAD_FORCE   (1<<1)
-extern int submodule_move_head(const char *path,
-			       const char *old,
-			       const char *new_head,
-			       unsigned flags);
+int submodule_move_head(const char *path,
+			const char *old,
+			const char *new_head,
+			unsigned flags);
 
 void submodule_unset_core_worktree(const struct submodule *sub);
 
@@ -128,18 +128,18 @@ void submodule_unset_core_worktree(const struct submodule *sub);
  * a submodule by clearing any repo-specific environment variables, but
  * retaining any config in the environment.
  */
-extern void prepare_submodule_repo_env(struct argv_array *out);
+void prepare_submodule_repo_env(struct argv_array *out);
 
 #define ABSORB_GITDIR_RECURSE_SUBMODULES (1<<0)
-extern void absorb_git_dir_into_superproject(const char *prefix,
-					     const char *path,
-					     unsigned flags);
+void absorb_git_dir_into_superproject(const char *prefix,
+				      const char *path,
+				      unsigned flags);
 
 /*
  * Return the absolute path of the working tree of the superproject, which this
  * project is a submodule of. If this repository is not a submodule of
  * another repository, return NULL.
  */
-extern const char *get_superproject_working_tree(void);
+const char *get_superproject_working_tree(void);
 
 #endif