diff --git a/src/core/ngx_inet.h b/src/core/ngx_inet.h
index 9f71444..f5f5e0d 100644
--- a/src/core/ngx_inet.h
+++ b/src/core/ngx_inet.h
@@ -2,8 +2,9 @@
 #define _NGX_INET_H_INCLUDED_
 
 
-size_t ngx_sock_ntop(int family, struct sockaddr *addr, char *text, size_t len);
-size_t ngx_inet_ntop(int family, char *addr, char *text, size_t len);
+size_t ngx_sock_ntop(int family, struct sockaddr *addr, u_char *text,
+                     size_t len);
+size_t ngx_inet_ntop(int family, u_char *addr, u_char *text, size_t len);
 
 
 #endif /* _NGX_INET_H_INCLUDED_ */