diff --git a/src/eval.c b/src/eval.c
index e92a97f..7ca129b 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -4339,10 +4339,17 @@
 		 * use its contents. */
 		s = deref_func_name(s, &len, &partial, !evaluate);
 
-		/* Invoke the function. */
-		ret = get_func_tv(s, len, rettv, arg,
-			  curwin->w_cursor.lnum, curwin->w_cursor.lnum,
-			  &len, evaluate, partial, NULL);
+		/* Need to make a copy, in case evaluating the arguments makes
+		 * the name invalid. */
+		s = vim_strsave(s);
+		if (s == NULL)
+		    ret = FAIL;
+		else
+		    /* Invoke the function. */
+		    ret = get_func_tv(s, len, rettv, arg,
+			      curwin->w_cursor.lnum, curwin->w_cursor.lnum,
+			      &len, evaluate, partial, NULL);
+		vim_free(s);
 
 		/* If evaluate is FALSE rettv->v_type was not set in
 		 * get_func_tv, but it's needed in handle_subscript() to parse
diff --git a/src/testdir/test_nested_function.vim b/src/testdir/test_nested_function.vim
index f881730..7e301ed 100644
--- a/src/testdir/test_nested_function.vim
+++ b/src/testdir/test_nested_function.vim
@@ -1,32 +1,42 @@
 "Tests for nested functions
 "
-function! NestedFunc()
-  fu! Func1()
+func NestedFunc()
+  func! Func1()
     let g:text .= 'Func1 '
-  endfunction
+  endfunc
   call Func1()
-  fu! s:func2()
+  func! s:func2()
     let g:text .= 's:func2 '
-  endfunction
+  endfunc
   call s:func2()
-  fu! s:_func3()
+  func! s:_func3()
     let g:text .= 's:_func3 '
-  endfunction
+  endfunc
   call s:_func3()
   let fn = 'Func4'
-  fu! {fn}()
+  func! {fn}()
     let g:text .= 'Func4 '
-  endfunction
+  endfunc
   call {fn}()
   let fn = 'func5'
-  fu! s:{fn}()
+  func! s:{fn}()
     let g:text .= 's:func5'
-  endfunction
+  endfunc
   call s:{fn}()
-endfunction
+endfunc
 
-function! Test_nested_functions()
+func Test_nested_functions()
   let g:text = ''
   call NestedFunc()
   call assert_equal('Func1 s:func2 s:_func3 Func4 s:func5', g:text)
 endfunction
+
+func Test_nested_argument()
+  func g:X()
+    let g:Y = function('sort')
+  endfunc
+  let g:Y = function('sort')
+  echo g:Y([], g:X())
+  delfunc g:X
+  unlet g:Y
+endfunc
diff --git a/src/version.c b/src/version.c
index c4013e7..8b30bae 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    85,
+/**/
     84,
 /**/
     83,