diff --git a/src/evalfunc.c b/src/evalfunc.c
index 40fb9e9..7170c0e 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -837,7 +837,7 @@
     {"sign_undefine",	0, 1, FEARG_1,	  ret_number,	SIGN_FUNC(f_sign_undefine)},
     {"sign_unplace",	1, 2, FEARG_1,	  ret_number,	SIGN_FUNC(f_sign_unplace)},
     {"sign_unplacelist", 1, 2, FEARG_1,	  ret_list_number, SIGN_FUNC(f_sign_unplacelist)},
-    {"simplify",	1, 1, 0,	  ret_string,	f_simplify},
+    {"simplify",	1, 1, FEARG_1,	  ret_string,	f_simplify},
     {"sin",		1, 1, FEARG_1,	  ret_float,	FLOAT_FUNC(f_sin)},
     {"sinh",		1, 1, FEARG_1,	  ret_float,	FLOAT_FUNC(f_sinh)},
     {"sort",		1, 3, FEARG_1,	  ret_list_any,	f_sort},
diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
index 427e404..2cf9006 100644
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -450,7 +450,7 @@
   call assert_equal('/',           simplify('/.'))
   call assert_equal('/',           simplify('/..'))
   call assert_equal('/...',        simplify('/...'))
-  call assert_equal('./dir/file',  simplify('./dir/file'))
+  call assert_equal('./dir/file',  './dir/file'->simplify())
   call assert_equal('./dir/file',  simplify('.///dir//file'))
   call assert_equal('./dir/file',  simplify('./dir/./file'))
   call assert_equal('./file',      simplify('./dir/../file'))
diff --git a/src/version.c b/src/version.c
index 63f811c..99ffd90 100644
--- a/src/version.c
+++ b/src/version.c
@@ -739,6 +739,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    532,
+/**/
     531,
 /**/
     530,