diff --git a/src/testdir/test_expr_utf8.vim b/src/testdir/test_expr_utf8.vim
index 8b10e63..ec36dec 100644
--- a/src/testdir/test_expr_utf8.vim
+++ b/src/testdir/test_expr_utf8.vim
@@ -6,13 +6,12 @@
 scriptencoding utf-8
 
 func Test_strgetchar()
-  call assert_equal(char2nr('a'), strgetchar('axb', 0))
-  call assert_equal(char2nr('x'), strgetchar('axb', 1))
-  call assert_equal(char2nr('b'), strgetchar('axb', 2))
+  call assert_equal(char2nr('á'), strgetchar('áxb', 0))
+  call assert_equal(char2nr('x'), strgetchar('áxb', 1))
 
-  call assert_equal(-1, strgetchar('axb', -1))
-  call assert_equal(-1, strgetchar('axb', 3))
-  call assert_equal(-1, strgetchar('', 0))
+  call assert_equal(char2nr('a'), strgetchar('àxb', 0))
+  call assert_equal(char2nr('̀'), strgetchar('àxb', 1))
+  call assert_equal(char2nr('x'), strgetchar('àxb', 2))
 endfunc
 
 func Test_strcharpart()