diff --git a/src/libraries/libisc-new/src/isc_abort.c b/src/libraries/libisc-new/src/isc_abort.c
index 8e1ac120cf5cd9e746fd202fa6e3202ce153175f..43ea5ca658ddca30aa6a8721a643ef82149ab4cc 100644
--- a/src/libraries/libisc-new/src/isc_abort.c
+++ b/src/libraries/libisc-new/src/isc_abort.c
@@ -17,10 +17,6 @@
 /*
 ** External function declarations
 */
-extern int fprintf(FILE *, char *, ...);
-#if defined(__sun__) && !defined(__stdlib_h)
-extern void abort(void);
-#endif
 
 static void (*isc_abortfn)(const char *msg) = (void (*)(const char *))NULL;
 
diff --git a/src/libraries/libisc-new/src/isc_message.c b/src/libraries/libisc-new/src/isc_message.c
index e9f9c9bc6a4c2b9a15c4644d431f3690398278af..4a3cf0ad3b5985deb8dd3d1a166a713af38e4d10 100644
--- a/src/libraries/libisc-new/src/isc_message.c
+++ b/src/libraries/libisc-new/src/isc_message.c
@@ -15,8 +15,6 @@
 #include "isc.h"
 #include "intern.h"
 
-extern void *memcpy(void *, void *, int);
-
 
 IscMessage *
 isc_allocmsg(size_t size)
diff --git a/src/libraries/libisc-new/src/isc_output.c b/src/libraries/libisc-new/src/isc_output.c
index dff4f4cf769e67668059d72f5220cbfec1c2d892..032c12798b45085ed80de79ce696b5cb1da1cb18 100644
--- a/src/libraries/libisc-new/src/isc_output.c
+++ b/src/libraries/libisc-new/src/isc_output.c
@@ -22,7 +22,6 @@
 /*
  * External function declarations
  */
-extern void *memcpy(void *, void *, int);
 extern char *strerror(int);