diff --git a/include/exports.h b/include/exports.h
index 63aa4b264a17e70687c5e2aab8851d374f2a9b45..6cf31aa5e794c0c6fb186bb6ee3705136cc40a2b 100644
--- a/include/exports.h
+++ b/include/exports.h
@@ -23,7 +23,7 @@ char *getenv (const char *name);
 int setenv (const char *varname, const char *varvalue);
 long simple_strtol(const char *cp,char **endp,unsigned int base);
 int strcmp(const char * cs,const char * ct);
-int ustrtoul(const char *cp, char **endp, unsigned int base);
+unsigned long ustrtoul(const char *cp, char **endp, unsigned int base);
 #if defined(CONFIG_CMD_I2C)
 int i2c_write (uchar, uint, int , uchar* , int);
 int i2c_read (uchar, uint, int , uchar* , int);
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index b7a79c0e0c90ea6a5bd275a4bdf0fd3853c5d610..3c432f8764fb7cf679e4e7260247eee6d9938853 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -103,7 +103,7 @@ long simple_strtol(const char *cp, char **endp, unsigned int base)
 	return simple_strtoul(cp, endp, base);
 }
 
-int ustrtoul(const char *cp, char **endp, unsigned int base)
+unsigned long ustrtoul(const char *cp, char **endp, unsigned int base)
 {
 	unsigned long result = simple_strtoul(cp, endp, base);
 	switch (**endp) {