diff --git a/src/nvim/path.c b/src/nvim/path.c
index 828b690699..d1e0947038 100644
--- a/src/nvim/path.c
+++ b/src/nvim/path.c
@@ -1810,7 +1810,7 @@ bool path_with_extension(const char *path, const char *extension)
   if (!last_dot) {
     return false;
   }
-  return strcmp(last_dot + 1, extension) == 0;
+  return mb_strcmp_ic((bool)p_fic, last_dot + 1, extension) == 0;
 }
 
 /// Return true if "name" is a full (absolute) path name or URL.
diff --git a/src/nvim/runtime.c b/src/nvim/runtime.c
index 9cd4a17b27..9614937c4c 100644
--- a/src/nvim/runtime.c
+++ b/src/nvim/runtime.c
@@ -275,7 +275,7 @@ static bool source_callback_vim_lua(int num_fnames, char **fnames, bool all, voi
   bool did_one = false;
 
   for (int i = 0; i < num_fnames; i++) {
-    if (str_ends_with(fnames[i], ".vim")) {
+    if (path_with_extension(fnames[i], "vim")) {
       (void)do_source(fnames[i], false, DOSO_NONE, cookie);
       did_one = true;
       if (!all) {
@@ -285,7 +285,7 @@ static bool source_callback_vim_lua(int num_fnames, char **fnames, bool all, voi
   }
 
   for (int i = 0; i < num_fnames; i++) {
-    if (str_ends_with(fnames[i], ".lua")) {
+    if (path_with_extension(fnames[i], "lua")) {
       (void)do_source(fnames[i], false, DOSO_NONE, cookie);
       did_one = true;
       if (!all) {
@@ -308,7 +308,8 @@ static bool source_callback(int num_fnames, char **fnames, bool all, void *cooki
   }
 
   for (int i = 0; i < num_fnames; i++) {
-    if (!str_ends_with(fnames[i], ".vim") && !str_ends_with(fnames[i], ".lua")) {
+    if (!path_with_extension(fnames[i], "vim")
+        && !path_with_extension(fnames[i], "lua")) {
       (void)do_source(fnames[i], false, DOSO_NONE, cookie);
       did_one = true;
       if (!all) {
diff --git a/src/nvim/strings.c b/src/nvim/strings.c
index 52a803a3cc..6fe2fd8ff3 100644
--- a/src/nvim/strings.c
+++ b/src/nvim/strings.c
@@ -436,25 +436,6 @@ char *vim_strchr(const char *const string, const int c)
   }
 }
 
-/// Test if "str" ends with "suffix"
-///
-/// @param[in] str
-/// @param[in] suffix to match
-///
-/// @return [allocated] Copy of the string.
-bool str_ends_with(const char *str, const char *suffix)
-{
-  if (!str || !suffix) {
-    return false;
-  }
-  size_t lenstr = strlen(str);
-  size_t lensuffix = strlen(suffix);
-  if (lensuffix > lenstr) {
-    return false;
-  }
-  return strncmp(str + lenstr - lensuffix, suffix, lensuffix) == 0;
-}
-
 // Sort an array of strings.
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
diff --git a/test/functional/lua/runtime_spec.lua b/test/functional/lua/runtime_spec.lua
index 1f312fc513..0b8b2234db 100644
--- a/test/functional/lua/runtime_spec.lua
+++ b/test/functional/lua/runtime_spec.lua
@@ -177,6 +177,31 @@ describe('runtime:', function()
       exec('setfiletype new-ft')
       eq('ABCDEFabcdef', eval('g:seq'))
     end)
+
+    it("'rtp' order is respected with 'fileignorecase'", function()
+      exec('set fileignorecase')
+      local after_ftplugin_folder = table.concat({plug_dir, 'after', 'ftplugin'}, sep)
+      mkdir_p(table.concat({ftplugin_folder, 'new-ft'}, sep))
+      mkdir_p(table.concat({after_ftplugin_folder, 'new-ft'}, sep))
+      exec('set rtp+=' .. plug_dir .. '/after')
+      exec('let g:seq = ""')
+      -- A .lua file is loaded after a .vim file if they only differ in extension.
+      -- All files in after/ftplugin/ are loaded after all files in ftplugin/.
+      write_file(table.concat({ftplugin_folder, 'new-ft.VIM'}, sep), [[let g:seq ..= 'A']])
+      write_file(table.concat({ftplugin_folder, 'new-ft.LUA'}, sep), [[vim.g.seq = vim.g.seq .. 'B']])
+      write_file(table.concat({ftplugin_folder, 'new-ft_a.vim'}, sep), [[let g:seq ..= 'C']])
+      write_file(table.concat({ftplugin_folder, 'new-ft_a.lua'}, sep), [[vim.g.seq = vim.g.seq .. 'D']])
+      write_file(table.concat({ftplugin_folder, 'new-ft', 'a.VIM'}, sep), [[let g:seq ..= 'E']])
+      write_file(table.concat({ftplugin_folder, 'new-ft', 'a.LUA'}, sep), [[vim.g.seq = vim.g.seq .. 'F']])
+      write_file(table.concat({after_ftplugin_folder, 'new-ft.vim'}, sep), [[let g:seq ..= 'a']])
+      write_file(table.concat({after_ftplugin_folder, 'new-ft.lua'}, sep), [[vim.g.seq = vim.g.seq .. 'b']])
+      write_file(table.concat({after_ftplugin_folder, 'new-ft_a.VIM'}, sep), [[let g:seq ..= 'c']])
+      write_file(table.concat({after_ftplugin_folder, 'new-ft_a.LUA'}, sep), [[vim.g.seq = vim.g.seq .. 'd']])
+      write_file(table.concat({after_ftplugin_folder, 'new-ft', 'a.vim'}, sep), [[let g:seq ..= 'e']])
+      write_file(table.concat({after_ftplugin_folder, 'new-ft', 'a.lua'}, sep), [[vim.g.seq = vim.g.seq .. 'f']])
+      exec('setfiletype new-ft')
+      eq('ABCDEFabcdef', eval('g:seq'))
+    end)
   end)
 
   describe('indent', function()
diff --git a/test/unit/path_spec.lua b/test/unit/path_spec.lua
index 5808e2013a..f9ce1ff099 100644
--- a/test/unit/path_spec.lua
+++ b/test/unit/path_spec.lua
@@ -15,6 +15,7 @@ local mkdir = helpers.mkdir
 
 cimport('string.h')
 local cimp = cimport('./src/nvim/os/os.h', './src/nvim/path.h')
+local options = cimport('./src/nvim/option_defs.h')
 
 local length = 0
 local buffer = nil
@@ -636,6 +637,15 @@ describe('path.c', function()
       eq(false, path_with_extension('/some/path/file.vim', 'lua'))
       eq(false, path_with_extension('/some/path/file', 'lua'))
     end)
+
+    itp("respects 'fileignorecase' option", function()
+      options.p_fic = false
+      eq(false, path_with_extension('/some/path/file.VIM', 'vim'))
+      eq(false, path_with_extension('/some/path/file.LUA', 'lua'))
+      options.p_fic = true
+      eq(true, path_with_extension('/some/path/file.VIM', 'vim'))
+      eq(true, path_with_extension('/some/path/file.LUA', 'lua'))
+    end)
   end)
 
   describe('path_with_url', function()