Index: libcio/conin.c
===================================================================
--- libcio/conin.c	(revision 48102540da3f449689e84a66567b30a9a3cca13f)
+++ libcio/conin.c	(revision 09d13458eaf73781ea49a7ff93d5b5297fa74f9b)
@@ -15,4 +15,6 @@
 	int16_t 	nbp;
 	register int16_t l;
+
+	(void)arg;
 
 	if (_ConBuf[1] EQ 0) {
Index: libcio/fseek.c
===================================================================
--- libcio/fseek.c	(revision 48102540da3f449689e84a66567b30a9a3cca13f)
+++ libcio/fseek.c	(revision 09d13458eaf73781ea49a7ff93d5b5297fa74f9b)
@@ -16,6 +16,5 @@
 int16_t fseek(FILE *fp, int32_t pos, int16_t mode)
 {
-	register int16_t i, lr;
-	int32_t curpos;
+	register int16_t lr;
 
 	if (fp->_flags & _DIRTY) {
Index: libcio/fsinit.c
===================================================================
--- libcio/fsinit.c	(revision 48102540da3f449689e84a66567b30a9a3cca13f)
+++ libcio/fsinit.c	(revision 09d13458eaf73781ea49a7ff93d5b5297fa74f9b)
@@ -41,4 +41,8 @@
 int16_t _badfio(io_arg arg, int8_t *buff, int16_t len)
 {
+	(void)arg;
+	(void)buff;
+	(void)len;
+
 	errno = EBADF;		/* set bad fd code */
 	return(FAILURE);	/* return with an error indication */
@@ -53,4 +57,6 @@
 int16_t _badfc(io_arg arg)
 {
+	(void)arg;
+
 	errno = EBADF;		/* set bad fd code */
 	return(FAILURE);	/* return with an error indication */
@@ -65,4 +71,10 @@
 int16_t _nopo(int8_t *name, int16_t flag, int16_t mode, struct channel *chp, struct devtabl *dp)
 {
+	(void)name;
+	(void)flag;
+	(void)mode;
+	(void)chp;
+	(void)dp;
+
 	return(SUCCESS);	/* return with a non-error indication */
 }
@@ -76,4 +88,6 @@
 int16_t _nopc(io_arg arg)
 {
+	(void)arg;
+
 	return(SUCCESS);	/* return with a non-error indication */
 }
Index: libcio/fstubs.c
===================================================================
--- libcio/fstubs.c	(revision 48102540da3f449689e84a66567b30a9a3cca13f)
+++ libcio/fstubs.c	(revision 09d13458eaf73781ea49a7ff93d5b5297fa74f9b)
@@ -38,4 +38,7 @@
 int16_t readbuf(int16_t dev, int8_t *buf)
 {
+	(void)dev;
+	(void)buf;
+
 	xtrap15();
 	return(1);
Index: libcio/open.c
===================================================================
--- libcio/open.c	(revision 48102540da3f449689e84a66567b30a9a3cca13f)
+++ libcio/open.c	(revision 09d13458eaf73781ea49a7ff93d5b5297fa74f9b)
@@ -179,4 +179,7 @@
 	int8_t	tmpname[9], tmpext[4];
 
+	(void)mode;
+	(void)dp;
+
 	/* search for an available fcb entry */
 
Index: libcio/rename.c
===================================================================
--- libcio/rename.c	(revision 48102540da3f449689e84a66567b30a9a3cca13f)
+++ libcio/rename.c	(revision 09d13458eaf73781ea49a7ff93d5b5297fa74f9b)
@@ -10,5 +10,6 @@
 int16_t rename(int8_t *old, int8_t *new)
 {
-	int8_t buff[60];
+	(void)old;
+	(void)new;
 
 	return(-1);		/* return an error for now */