diff --git a/src/include/os/sun4/osiSock.h b/src/include/os/sun4/osiSock.h
index 474364008..75d89c996 100644
--- a/src/include/os/sun4/osiSock.h
+++ b/src/include/os/sun4/osiSock.h
@@ -78,6 +78,7 @@ int gethostname (char *name, int namelen);
 #	define h_addr  h_addr_list[0]  /* address, for backward compatiblity */
 	};
 	struct hostent *gethostbyaddr(char *addr, int len, int type);
+	struct hostent *gethostnyname(const char *name);
 
 #endif /* !defined(__SUNPRO_CC) */
 
diff --git a/src/libCom/osi/os/sun4/osdSock.h b/src/libCom/osi/os/sun4/osdSock.h
index 474364008..75d89c996 100644
--- a/src/libCom/osi/os/sun4/osdSock.h
+++ b/src/libCom/osi/os/sun4/osdSock.h
@@ -78,6 +78,7 @@ int gethostname (char *name, int namelen);
 #	define h_addr  h_addr_list[0]  /* address, for backward compatiblity */
 	};
 	struct hostent *gethostbyaddr(char *addr, int len, int type);
+	struct hostent *gethostnyname(const char *name);
 
 #endif /* !defined(__SUNPRO_CC) */