diff --git a/src/nvim/autocmd.c b/src/nvim/autocmd.c
index 2460119123..83f81309e0 100644
--- a/src/nvim/autocmd.c
+++ b/src/nvim/autocmd.c
@@ -1566,7 +1566,7 @@ bool has_event(event_T event) FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
 
 /// Return true when there is a CursorHold/CursorHoldI autocommand defined for
 /// the current mode.
-bool has_cursorhold(void) FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
+static bool has_cursorhold(void) FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
 {
   return has_event((get_real_state() == MODE_NORMAL_BUSY ? EVENT_CURSORHOLD : EVENT_CURSORHOLDI));
 }
diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index c2e26e5f3d..3f88064ca8 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -1683,7 +1683,7 @@ void set_curbuf(buf_T *buf, int action, bool update_jumplist)
 /// Enter a new current buffer.
 /// Old curbuf must have been abandoned already!  This also means "curbuf" may
 /// be pointing to freed memory.
-void enter_buffer(buf_T *buf)
+static void enter_buffer(buf_T *buf)
 {
   // when closing the current buffer stop Visual mode
   if (VIsual_active
@@ -2207,7 +2207,7 @@ int buflist_getfile(int n, linenr_T lnum, int options, int forceit)
 }
 
 /// Go to the last known line number for the current buffer.
-void buflist_getfpos(void)
+static void buflist_getfpos(void)
 {
   pos_T *fpos = &buflist_findfmark(curbuf)->mark;
 
diff --git a/src/nvim/digraph.c b/src/nvim/digraph.c
index f32123e686..143335b5b0 100644
--- a/src/nvim/digraph.c
+++ b/src/nvim/digraph.c
@@ -1791,7 +1791,7 @@ void digraph_getlist_common(bool list_all, typval_T *rettv)
   }
 }
 
-struct dg_header_entry {
+static struct dg_header_entry {
   int dg_start;
   const char *dg_header;
 } header_table[] = {
diff --git a/src/nvim/eval/typval.c b/src/nvim/eval/typval.c
index f9cf245e50..8a44b180da 100644
--- a/src/nvim/eval/typval.c
+++ b/src/nvim/eval/typval.c
@@ -190,7 +190,7 @@ void tv_list_watch_remove(list_T *const l, listwatch_T *const lwrem)
 ///
 /// @param[out]  l  List from which item is removed.
 /// @param[in]  item  List item being removed.
-void tv_list_watch_fix(list_T *const l, const listitem_T *const item)
+static void tv_list_watch_fix(list_T *const l, const listitem_T *const item)
   FUNC_ATTR_NONNULL_ALL
 {
   for (listwatch_T *lw = l->lv_watch; lw != NULL; lw = lw->lw_next) {
diff --git a/src/nvim/ex_cmds.c b/src/nvim/ex_cmds.c
index 36cca6cf22..fcd5fcdd9e 100644
--- a/src/nvim/ex_cmds.c
+++ b/src/nvim/ex_cmds.c
@@ -2144,7 +2144,7 @@ void do_wqall(exarg_T *eap)
 /// Check the 'write' option.
 ///
 /// @return  true and give a message when it's not st.
-bool not_writing(void)
+static bool not_writing(void)
 {
   if (p_write) {
     return false;
diff --git a/src/nvim/ex_eval.c b/src/nvim/ex_eval.c
index 18c691d076..424ee07779 100644
--- a/src/nvim/ex_eval.c
+++ b/src/nvim/ex_eval.c
@@ -799,7 +799,7 @@ void report_make_pending(int pending, void *value)
 
 /// If something pending in a finally clause is resumed at the ":endtry", report
 /// it if required by the 'verbose' option or when debugging.
-void report_resume_pending(int pending, void *value)
+static void report_resume_pending(int pending, void *value)
 {
   if (p_verbose >= 14 || debug_break_level > 0) {
     if (debug_break_level <= 0) {
@@ -814,7 +814,7 @@ void report_resume_pending(int pending, void *value)
 
 /// If something pending in a finally clause is discarded, report it if required
 /// by the 'verbose' option or when debugging.
-void report_discard_pending(int pending, void *value)
+static void report_discard_pending(int pending, void *value)
 {
   if (p_verbose >= 14 || debug_break_level > 0) {
     if (debug_break_level <= 0) {
diff --git a/src/nvim/file_search.c b/src/nvim/file_search.c
index c882777f1c..3c9290c308 100644
--- a/src/nvim/file_search.c
+++ b/src/nvim/file_search.c
@@ -1031,7 +1031,7 @@ fail:
 
 /// Free the list of lists of visited files and directories
 /// Can handle it if the passed search_context is NULL;
-void vim_findfile_free_visited(void *search_ctx_arg)
+static void vim_findfile_free_visited(void *search_ctx_arg)
 {
   if (search_ctx_arg == NULL) {
     return;
diff --git a/src/nvim/getchar.c b/src/nvim/getchar.c
index c945d878fc..28338e026e 100644
--- a/src/nvim/getchar.c
+++ b/src/nvim/getchar.c
@@ -1282,7 +1282,7 @@ void may_sync_undo(void)
 }
 
 /// Make "typebuf" empty and allocate new buffers.
-void alloc_typebuf(void)
+static void alloc_typebuf(void)
 {
   typebuf.tb_buf = xmalloc(TYPELEN_INIT);
   typebuf.tb_noremap = xmalloc(TYPELEN_INIT);
@@ -1298,7 +1298,7 @@ void alloc_typebuf(void)
 }
 
 /// Free the buffers of "typebuf".
-void free_typebuf(void)
+static void free_typebuf(void)
 {
   if (typebuf.tb_buf == typebuf_init) {
     internal_error("Free typebuf 1");
diff --git a/src/nvim/indent.c b/src/nvim/indent.c
index e1acfc34ef..70d83cea2e 100644
--- a/src/nvim/indent.c
+++ b/src/nvim/indent.c
@@ -335,7 +335,7 @@ int get_sw_value(buf_T *buf)
 }
 
 /// Idem, using "pos".
-int get_sw_value_pos(buf_T *buf, pos_T *pos, bool left)
+static int get_sw_value_pos(buf_T *buf, pos_T *pos, bool left)
 {
   pos_T save_cursor = curwin->w_cursor;
 
diff --git a/src/nvim/indent_c.c b/src/nvim/indent_c.c
index 89eac1e5d2..345d1a7720 100644
--- a/src/nvim/indent_c.c
+++ b/src/nvim/indent_c.c
@@ -355,7 +355,7 @@ static bool cin_islabel_skip(const char **s)
 
 // Recognize a label: "label:".
 // Note: curwin->w_cursor must be where we are looking for the label.
-bool cin_islabel(void)  // XXX
+static bool cin_islabel(void)  // XXX
 {
   const char *s = cin_skipcomment(get_cursor_line_ptr());
 
@@ -454,7 +454,7 @@ static int cin_isinit(void)
 /// Recognize a switch label: "case .*:" or "default:".
 ///
 /// @param strict  Allow relaxed check of case statement for JS
-bool cin_iscase(const char *s, bool strict)
+static bool cin_iscase(const char *s, bool strict)
 {
   s = cin_skipcomment(s);
   if (cin_starts_with(s, "case")) {
@@ -500,7 +500,7 @@ static int cin_isdefault(const char *s)
 }
 
 /// Recognize a scope declaration label set in 'cinscopedecls'.
-bool cin_isscopedecl(const char *p)
+static bool cin_isscopedecl(const char *p)
 {
   const char *s = cin_skipcomment(p);
 
diff --git a/src/nvim/menu.c b/src/nvim/menu.c
index 5762e43e94..d465b3e70f 100644
--- a/src/nvim/menu.c
+++ b/src/nvim/menu.c
@@ -1090,7 +1090,7 @@ char *get_menu_names(expand_T *xp, int idx)
 ///
 /// @param name may be modified.
 /// @return start of the next element
-char *menu_name_skip(char *const name)
+static char *menu_name_skip(char *const name)
 {
   char *p;
 
diff --git a/src/nvim/message.c b/src/nvim/message.c
index 5c96fb9f73..94faab771b 100644
--- a/src/nvim/message.c
+++ b/src/nvim/message.c
@@ -662,7 +662,7 @@ void msg_source(int hl_id)
 ///            If "emsg_off" is set: no error messages at the moment.
 ///            If "msg" is in 'debug': do error message but without side effects.
 ///            If "emsg_skip" is set: never do error messages.
-int emsg_not_now(void)
+static int emsg_not_now(void)
 {
   if ((emsg_off > 0 && vim_strchr(p_debug, 'm') == NULL
        && vim_strchr(p_debug, 't') == NULL)
@@ -3045,7 +3045,7 @@ static bool do_more_prompt(int typed_char)
   return retval;
 }
 
-void msg_moremsg(bool full)
+static void msg_moremsg(bool full)
 {
   int attr = hl_combine_attr(HL_ATTR(HLF_MSG), HL_ATTR(HLF_M));
   grid_line_start(&msg_grid_adj, Rows - 1);
@@ -3739,7 +3739,7 @@ static void copy_confirm_hotkeys(const char *buttons, int default_button_idx,
 }
 
 /// Display the ":confirm" message.  Also called when screen resized.
-void display_confirm_msg(void)
+static void display_confirm_msg(void)
 {
   // Avoid that 'q' at the more prompt truncates the message here.
   confirm_msg_used++;
diff --git a/src/nvim/option.c b/src/nvim/option.c
index 9f51d28b33..0d62e705a2 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -4916,7 +4916,7 @@ void copy_winopt(winopt_T *from, winopt_T *to)
 }
 
 /// Check string options in a window for a NULL value.
-void check_win_options(win_T *win)
+static void check_win_options(win_T *win)
 {
   check_winopt(&win->w_onebuf_opt);
   check_winopt(&win->w_allbuf_opt);
diff --git a/src/nvim/profile.c b/src/nvim/profile.c
index 627f06c9ce..9462f5b285 100644
--- a/src/nvim/profile.c
+++ b/src/nvim/profile.c
@@ -171,7 +171,7 @@ proftime_T profile_self(proftime_T self, proftime_T total, proftime_T children)
 /// Gets the current waittime.
 ///
 /// @return the current waittime
-proftime_T profile_get_wait(void) FUNC_ATTR_PURE
+static proftime_T profile_get_wait(void) FUNC_ATTR_PURE
 {
   return prof_wait_time;
 }
@@ -194,7 +194,7 @@ proftime_T profile_sub_wait(proftime_T tm, proftime_T tma) FUNC_ATTR_PURE
 /// Checks if time `tm1` is equal to `tm2`.
 ///
 /// @return true if `tm1` == `tm2`
-bool profile_equal(proftime_T tm1, proftime_T tm2) FUNC_ATTR_CONST
+static bool profile_equal(proftime_T tm1, proftime_T tm2) FUNC_ATTR_CONST
 {
   return tm1 == tm2;
 }
diff --git a/src/nvim/undo.c b/src/nvim/undo.c
index 8d791a4c38..e878fe2709 100644
--- a/src/nvim/undo.c
+++ b/src/nvim/undo.c
@@ -2991,7 +2991,7 @@ void u_clearallandblockfree(buf_T *buf)
 }
 
 /// Save the line "lnum" for the "U" command.
-void u_saveline(buf_T *buf, linenr_T lnum)
+static void u_saveline(buf_T *buf, linenr_T lnum)
 {
   if (lnum == buf->b_u_line_lnum) {      // line is already saved
     return;
diff --git a/src/nvim/window.c b/src/nvim/window.c
index 92b8eab184..b38799514a 100644
--- a/src/nvim/window.c
+++ b/src/nvim/window.c
@@ -4262,7 +4262,7 @@ int win_new_tabpage(int after, char *filename)
 // Open a new tab page if ":tab cmd" was used.  It will edit the same buffer,
 // like with ":split".
 // Returns OK if a new tab page was created, FAIL otherwise.
-int may_open_tabpage(void)
+static int may_open_tabpage(void)
 {
   int n = (cmdmod.cmod_tab == 0) ? postponed_split_tab : cmdmod.cmod_tab;
 
diff --git a/test/unit/profile_spec.lua b/test/unit/profile_spec.lua
index 27b817cf42..ed760c37d9 100644
--- a/test/unit/profile_spec.lua
+++ b/test/unit/profile_spec.lua
@@ -96,9 +96,6 @@ describe('profiling related functions', function()
   local function profile_cmp(t1, t2)
     return prof.profile_cmp(t1, t2)
   end
-  local function profile_equal(t1, t2)
-    return prof.profile_equal(t1, t2)
-  end
   local function profile_msg(q)
     return ffi.string(prof.profile_msg(q))
   end
@@ -110,20 +107,6 @@ describe('profiling related functions', function()
     return tonumber(s) + tonumber(us) / 1000000
   end
 
-  describe('profile_equal', function()
-    itp('times are equal to themselves', function()
-      local start = profile_start()
-      assert.is_true(profile_equal(start, start))
-
-      local e = profile_end(start)
-      assert.is_true(profile_equal(e, e))
-    end)
-
-    itp('times are unequal to others', function()
-      assert.is_false(profile_equal(profile_start(), profile_start()))
-    end)
-  end)
-
   -- this is quite difficult to test, as it would rely on other functions in
   -- the profiling package. Those functions in turn will probably be tested
   -- using profile_cmp... circular reasoning.
@@ -169,7 +152,6 @@ describe('profiling related functions', function()
   describe('profile_zero', function()
     itp('returns the same value on each call', function()
       eq(0, profile_zero())
-      assert.is_true(profile_equal(profile_zero(), profile_zero()))
     end)
   end)
 
@@ -203,7 +185,7 @@ describe('profiling related functions', function()
 
   describe('profile_setlimit', function()
     itp('sets no limit when 0 is passed', function()
-      eq(true, profile_equal(profile_setlimit(0), profile_zero()))
+      eq(profile_setlimit(0), profile_zero())
     end)
 
     itp('sets a limit in the future otherwise', function()