diff --git a/src/testdir/test_expr.vim b/src/testdir/test_expr.vim
index b4eeea6..cfae760 100644
--- a/src/testdir/test_expr.vim
+++ b/src/testdir/test_expr.vim
@@ -599,6 +599,11 @@
   call assert_fails("let v = -{}", 'E728:')
 endfunc
 
+func Test_white_in_function_call()
+  let text = substitute ( 'some text' , 't' , 'T' , 'g' )
+  call assert_equal('some TexT', text)
+endfunc
+
 " Test for float value comparison
 func Test_float_compare()
   CheckFeature float