diff --git a/src/eval.c b/src/eval.c
index 7708796..2256589 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -26439,9 +26439,11 @@
     {
 	/* vim_strsave_shellescape() needs a NUL terminated string. */
 	c = (*fnamep)[*fnamelen];
-	(*fnamep)[*fnamelen] = NUL;
+	if (c != NUL)
+	    (*fnamep)[*fnamelen] = NUL;
 	p = vim_strsave_shellescape(*fnamep, FALSE, FALSE);
-	(*fnamep)[*fnamelen] = c;
+	if (c != NUL)
+	    (*fnamep)[*fnamelen] = c;
 	if (p == NULL)
 	    return -1;
 	vim_free(*bufp);
diff --git a/src/testdir/test_fnamemodify.vim b/src/testdir/test_fnamemodify.vim
index 902be40..2267e18 100644
--- a/src/testdir/test_fnamemodify.vim
+++ b/src/testdir/test_fnamemodify.vim
@@ -41,3 +41,9 @@
   call assert_equal("'abc\\\ndef'",  fnamemodify("abc\ndef", ':S'))
   set shell&
 endfunc
+
+func Test_expand()
+  new
+  call assert_equal("",  expand('%:S'))
+  quit
+endfunc
diff --git a/src/version.c b/src/version.c
index 1e8c419..c1f6db6 100644
--- a/src/version.c
+++ b/src/version.c
@@ -749,6 +749,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1654,
+/**/
     1653,
 /**/
     1652,