diff --git a/src/testdir/test_vimscript.vim b/src/testdir/test_vimscript.vim
index a9d246b..72eae7c 100644
--- a/src/testdir/test_vimscript.vim
+++ b/src/testdir/test_vimscript.vim
@@ -1737,6 +1737,8 @@
       call assert_equal(4.2, x)
       call assert_fails('let x %= 0.5', 'E734')
       call assert_fails('let x .= "f"', 'E734')
+      let x = !3.14
+      call assert_equal(0.0, x)
     endif
 
     " Test for environment variable
@@ -2083,6 +2085,20 @@
   delfunc Xfunc
 endfunc
 
+" Test for errors in converting to float from various types         {{{1
+func Test_float_conversion_errors()
+  if has('float')
+    call assert_fails('let x = 4.0 % 2.0', 'E804')
+    call assert_fails('echo 1.1[0]', 'E806')
+    call assert_fails('echo sort([function("min"), 1], "f")', 'E891:')
+    call assert_fails('echo 3.2 == "vim"', 'E892:')
+    call assert_fails('echo sort([[], 1], "f")', 'E893:')
+    call assert_fails('echo sort([{}, 1], "f")', 'E894:')
+    call assert_fails('echo 3.2 == v:true', 'E362:')
+    call assert_fails('echo 3.2 == v:none', 'E907:')
+  endif
+endfunc
+
 "-------------------------------------------------------------------------------
 " Modelines								    {{{1
 " vim: ts=8 sw=2 sts=2 expandtab tw=80 fdm=marker