diff --git a/src/vim.h b/src/vim.h
index 0204aa3..2c2848c 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -1599,6 +1599,11 @@
 #  define STRICMP(d, s)	    vim_stricmp((char *)(d), (char *)(s))
 # endif
 #endif
+#ifdef HAVE_STRCOLL
+# define STRCOLL(d, s)     strcoll((char *)(d), (char *)(s))
+#else
+# define STRCOLL(d, s)     strcmp((char *)(d), (char *)(s))
+#endif
 
 // Like strcpy() but allows overlapped source and destination.
 #define STRMOVE(d, s)	    mch_memmove((d), (s), STRLEN(s) + 1)
@@ -1896,7 +1901,7 @@
 #define VALID_PATH		1
 #define VALID_HEAD		2
 
-// Defines for Vim variables.  These must match vimvars[] in eval.c!
+// Defines for Vim variables.  These must match vimvars[] in evalvars.c!
 #define VV_COUNT	0
 #define VV_COUNT1	1
 #define VV_PREVCOUNT	2
@@ -1992,7 +1997,8 @@
 #define VV_VERSIONLONG	92
 #define VV_ECHOSPACE	93
 #define VV_ARGV		94
-#define VV_LEN		95	// number of v: vars
+#define VV_COLLATE      95
+#define VV_LEN		96	// number of v: vars
 
 // used for v_number in VAR_BOOL and VAR_SPECIAL
 #define VVAL_FALSE	0L	// VAR_BOOL
@@ -2669,4 +2675,10 @@
 #define FSK_IN_STRING	0x04	// TRUE in string, double quote is escaped
 #define FSK_SIMPLIFY	0x08	// simplify <C-H> and <A-x>
 
+// Flags for the readdirex function, how to sort the result
+#define READDIR_SORT_NONE	0  // do not sort
+#define READDIR_SORT_BYTE	1  // sort by byte order (strcmp), default
+#define READDIR_SORT_IC		2  // sort ignoring case (strcasecmp)
+#define READDIR_SORT_COLLATE	3  // sort according to collation (strcoll)
+
 #endif // VIM__H