diff --git a/src/nvim/testdir/test75.in b/src/nvim/testdir/test75.in
deleted file mode 100644
index 8fabccdf52..0000000000
--- a/src/nvim/testdir/test75.in
+++ /dev/null
@@ -1,41 +0,0 @@
-Tests for maparg().
-Also test utf8 map with a 0x80 byte.
-
-STARTTEST
-:so small.vim
-:so mbyte.vim
-:set cpo-=<
-:set encoding=utf8
-:" Test maparg() with a string result
-:map foo<C-V> is<F4>foo
-:vnoremap <script> <buffer> <expr> <silent> bar isbar
-:call append('$', maparg('foo<C-V>'))
-:call append('$', string(maparg('foo<C-V>', '', 0, 1)))
-:call append('$', string(maparg('bar', '', 0, 1)))
-:map <buffer> <nowait> foo bar
-:call append('$', string(maparg('foo', '', 0, 1)))
-:"
-:map abc x<char-114>x
-:call append('$', maparg('abc'))
-:map abc y<S-char-114>y
-:call append('$', maparg('abc'))
-:"
-Go:"
-:" Outside of the range, minimum
-:inoremap <Char-0x1040> a
-:execute "normal a\u1040\<Esc>"
-:" Inside of the range, minimum
-:inoremap <Char-0x103f> b
-:execute "normal a\u103f\<Esc>"
-:" Inside of the range, maximum
-:inoremap <Char-0xf03f> c
-:execute "normal a\uf03f\<Esc>"
-:" Outside of the range, maximum
-:inoremap <Char-0xf040> d
-:execute "normal a\uf040\<Esc>"
-:"
-:/^eof/+1,$w! test.out
-:qa!
-ENDTEST
-
-eof
diff --git a/src/nvim/testdir/test75.ok b/src/nvim/testdir/test75.ok
deleted file mode 100644
index a2c5c5ac3d..0000000000
--- a/src/nvim/testdir/test75.ok
+++ /dev/null
@@ -1,7 +0,0 @@
-is<F4>foo
-{'silent': 0, 'noremap': 0, 'lhs': 'foo<C-V>', 'mode': ' ', 'nowait': 0, 'expr': 0, 'sid': 0, 'rhs': 'is<F4>foo', 'buffer': 0}
-{'silent': 1, 'noremap': 1, 'lhs': 'bar', 'mode': 'v', 'nowait': 0, 'expr': 1, 'sid': 0, 'rhs': 'isbar', 'buffer': 1}
-{'silent': 0, 'noremap': 0, 'lhs': 'foo', 'mode': ' ', 'nowait': 1, 'expr': 0, 'sid': 0, 'rhs': 'bar', 'buffer': 1}
-xrx
-yRy
-abcd
diff --git a/test/functional/legacy/075_maparg_spec.lua b/test/functional/legacy/075_maparg_spec.lua
new file mode 100644
index 0000000000..dac8940314
--- /dev/null
+++ b/test/functional/legacy/075_maparg_spec.lua
@@ -0,0 +1,58 @@
+-- Tests for maparg().
+-- Also test utf8 map with a 0x80 byte.
+
+local helpers = require('test.functional.helpers')
+local clear, feed, insert = helpers.clear, helpers.feed, helpers.insert
+local execute, expect = helpers.execute, helpers.expect
+
+describe('maparg()', function()
+  setup(clear)
+
+  it('is working', function()
+    execute('set cpo-=<')
+    execute('set encoding=utf8')
+
+    -- Test maparg() with a string result
+    execute('map foo<C-V> is<F4>foo')
+    execute('vnoremap <script> <buffer> <expr> <silent> bar isbar')
+    execute([[call append('$', maparg('foo<C-V>'))]])
+    execute([[call append('$', string(maparg('foo<C-V>', '', 0, 1)))]])
+    execute([[call append('$', string(maparg('bar', '', 0, 1)))]])
+    execute('map <buffer> <nowait> foo bar')
+    execute([[call append('$', string(maparg('foo', '', 0, 1)))]])
+    execute('map abc x<char-114>x')
+    execute([[call append('$', maparg('abc'))]])
+    execute('map abc y<S-char-114>y')
+    execute([[call append('$', maparg('abc'))]])
+    feed('Go<esc>:<cr>')
+
+    -- Outside of the range, minimum
+    execute('inoremap <Char-0x1040> a')
+    execute([[execute "normal a\u1040\<Esc>"]])
+
+    -- Inside of the range, minimum
+    execute('inoremap <Char-0x103f> b')
+    execute([[execute "normal a\u103f\<Esc>"]])
+
+    -- Inside of the range, maximum
+    execute('inoremap <Char-0xf03f> c')
+    execute([[execute "normal a\uf03f\<Esc>"]])
+
+    -- Outside of the range, maximum
+    execute('inoremap <Char-0xf040> d')
+    execute([[execute "normal a\uf040\<Esc>"]])
+
+    -- Remove empty line
+    execute('1d')
+
+    -- Assert buffer contents.
+    expect([[
+      is<F4>foo
+      {'silent': 0, 'noremap': 0, 'lhs': 'foo<C-V>', 'mode': ' ', 'nowait': 0, 'expr': 0, 'sid': 0, 'rhs': 'is<F4>foo', 'buffer': 0}
+      {'silent': 1, 'noremap': 1, 'lhs': 'bar', 'mode': 'v', 'nowait': 0, 'expr': 1, 'sid': 0, 'rhs': 'isbar', 'buffer': 1}
+      {'silent': 0, 'noremap': 0, 'lhs': 'foo', 'mode': ' ', 'nowait': 1, 'expr': 0, 'sid': 0, 'rhs': 'bar', 'buffer': 1}
+      xrx
+      yRy
+      abcd]])
+  end)
+end)