Index: uspace/lib/riff/include/riff/chunk.h
===================================================================
--- uspace/lib/riff/include/riff/chunk.h	(revision d53af3c8e49cf53bc3b0b68fb0fcadb78291e77f)
+++ uspace/lib/riff/include/riff/chunk.h	(revision 0ee3157bf2b87f9bff38e12dfecd8d9b3ec96139)
@@ -37,20 +37,21 @@
 #define RIFF_CHUNK_H
 
+#include <errno.h>
 #include <stddef.h>
 #include <types/riff/chunk.h>
 
-extern int riff_wopen(const char *, riffw_t **);
-extern int riff_wclose(riffw_t *);
-extern int riff_wchunk_start(riffw_t *, riff_ckid_t, riff_wchunk_t *);
-extern int riff_wchunk_end(riffw_t *, riff_wchunk_t *);
-extern int riff_wchunk_write(riffw_t *, void *, size_t);
-extern int riff_write_uint32(riffw_t *, uint32_t);
+extern errno_t riff_wopen(const char *, riffw_t **);
+extern errno_t riff_wclose(riffw_t *);
+extern errno_t riff_wchunk_start(riffw_t *, riff_ckid_t, riff_wchunk_t *);
+extern errno_t riff_wchunk_end(riffw_t *, riff_wchunk_t *);
+extern errno_t riff_wchunk_write(riffw_t *, void *, size_t);
+extern errno_t riff_write_uint32(riffw_t *, uint32_t);
 
-extern int riff_ropen(const char *, riffr_t **);
-extern int riff_rclose(riffr_t *);
-extern int riff_read_uint32(riffr_t *, uint32_t *);
-extern int riff_rchunk_start(riffr_t *, riff_rchunk_t *);
-extern int riff_rchunk_end(riffr_t *, riff_rchunk_t *);
-extern int riff_rchunk_read(riffr_t *, riff_rchunk_t *, void *, size_t,
+extern errno_t riff_ropen(const char *, riffr_t **);
+extern errno_t riff_rclose(riffr_t *);
+extern errno_t riff_read_uint32(riffr_t *, uint32_t *);
+extern errno_t riff_rchunk_start(riffr_t *, riff_rchunk_t *);
+extern errno_t riff_rchunk_end(riffr_t *, riff_rchunk_t *);
+extern errno_t riff_rchunk_read(riffr_t *, riff_rchunk_t *, void *, size_t,
     size_t *);
 
Index: uspace/lib/riff/include/riff/rwave.h
===================================================================
--- uspace/lib/riff/include/riff/rwave.h	(revision d53af3c8e49cf53bc3b0b68fb0fcadb78291e77f)
+++ uspace/lib/riff/include/riff/rwave.h	(revision 0ee3157bf2b87f9bff38e12dfecd8d9b3ec96139)
@@ -37,13 +37,14 @@
 #define RIFF_WAVE_H
 
+#include <errno.h>
 #include <types/riff/rwave.h>
 
-extern int rwave_wopen(const char *, rwave_params_t *params, rwavew_t **);
-extern int rwave_write_samples(rwavew_t *, void *, size_t);
-extern int rwave_wclose(rwavew_t *);
+extern errno_t rwave_wopen(const char *, rwave_params_t *params, rwavew_t **);
+extern errno_t rwave_write_samples(rwavew_t *, void *, size_t);
+extern errno_t rwave_wclose(rwavew_t *);
 
-extern int rwave_ropen(const char *, rwave_params_t *params, rwaver_t **);
-extern int rwave_read_samples(rwaver_t *, void *, size_t, size_t *);
-extern int rwave_rclose(rwaver_t *);
+extern errno_t rwave_ropen(const char *, rwave_params_t *params, rwaver_t **);
+extern errno_t rwave_read_samples(rwaver_t *, void *, size_t, size_t *);
+extern errno_t rwave_rclose(rwaver_t *);
 
 #endif
Index: uspace/lib/riff/src/chunk.c
===================================================================
--- uspace/lib/riff/src/chunk.c	(revision d53af3c8e49cf53bc3b0b68fb0fcadb78291e77f)
+++ uspace/lib/riff/src/chunk.c	(revision 0ee3157bf2b87f9bff38e12dfecd8d9b3ec96139)
@@ -49,5 +49,5 @@
  *         file.
  */
-int riff_wopen(const char *fname, riffw_t **rrw)
+errno_t riff_wopen(const char *fname, riffw_t **rrw)
 {
 	riffw_t *rw;
@@ -73,5 +73,5 @@
  *         is destroyed anyway.
  */
-int riff_wclose(riffw_t *rw)
+errno_t riff_wclose(riffw_t *rw)
 {
 	int rv;
@@ -89,5 +89,5 @@
  * @return EOK on success, EIO on error.
  */
-int riff_write_uint32(riffw_t *rw, uint32_t v)
+errno_t riff_write_uint32(riffw_t *rw, uint32_t v)
 {
 	uint32_t vle;
@@ -108,8 +108,8 @@
  * @return EOK on success, EIO on write error
  */
-int riff_wchunk_start(riffw_t *rw, riff_ckid_t ckid, riff_wchunk_t *wchunk)
+errno_t riff_wchunk_start(riffw_t *rw, riff_ckid_t ckid, riff_wchunk_t *wchunk)
 {
 	long pos;
-	int rc;
+	errno_t rc;
 
 	pos = ftell(rw->f);
@@ -141,9 +141,9 @@
  * @return EOK on success, EIO error.
  */
-int riff_wchunk_end(riffw_t *rw, riff_wchunk_t *wchunk)
+errno_t riff_wchunk_end(riffw_t *rw, riff_wchunk_t *wchunk)
 {
 	long pos;
 	long cksize;
-	int rc;
+	errno_t rc;
 
 	pos = ftell(rw->f);
@@ -176,5 +176,5 @@
  * @return EOK on success, EIO on error.
  */
-int riff_wchunk_write(riffw_t *rw, void *data, size_t bytes)
+errno_t riff_wchunk_write(riffw_t *rw, void *data, size_t bytes)
 {
 	size_t nw;
@@ -195,8 +195,8 @@
  *         file..
  */
-int riff_ropen(const char *fname, riffr_t **rrr)
+errno_t riff_ropen(const char *fname, riffr_t **rrr)
 {
 	riffr_t *rr;
-	int rc;
+	errno_t rc;
 
 	rr = calloc(1, sizeof(riffr_t));
@@ -226,7 +226,7 @@
  * @return EOK on success, EIO on error.
  */
-int riff_rclose(riffr_t *rr)
-{
-	int rc;
+errno_t riff_rclose(riffr_t *rr)
+{
+	errno_t rc;
 
 	rc = fclose(rr->f);
@@ -241,5 +241,5 @@
  * @return EOK on success, EIO on error.
  */
-int riff_read_uint32(riffr_t *rr, uint32_t *v)
+errno_t riff_read_uint32(riffr_t *rr, uint32_t *v)
 {
 	uint32_t vle;
@@ -259,7 +259,7 @@
  * @return EOK on success, EIO on error.
  */
-int riff_rchunk_start(riffr_t *rr, riff_rchunk_t *rchunk)
-{
-	int rc;
+errno_t riff_rchunk_start(riffr_t *rr, riff_rchunk_t *rchunk)
+{
+	errno_t rc;
 	long pos;
 
@@ -317,5 +317,5 @@
  * @return EOK on success, EIO on error.
  */
-int riff_rchunk_end(riffr_t *rr, riff_rchunk_t *rchunk)
+errno_t riff_rchunk_end(riffr_t *rr, riff_rchunk_t *rchunk)
 {
 	long ckend;
@@ -343,5 +343,5 @@
  *         EIO on I/O error.
  */
-int riff_rchunk_read(riffr_t *rr, riff_rchunk_t *rchunk, void *buf,
+errno_t riff_rchunk_read(riffr_t *rr, riff_rchunk_t *rchunk, void *buf,
     size_t bytes, size_t *nread)
 {
Index: uspace/lib/riff/src/rwave.c
===================================================================
--- uspace/lib/riff/src/rwave.c	(revision d53af3c8e49cf53bc3b0b68fb0fcadb78291e77f)
+++ uspace/lib/riff/src/rwave.c	(revision 0ee3157bf2b87f9bff38e12dfecd8d9b3ec96139)
@@ -94,9 +94,9 @@
  * @return EOK on success, EIO on I/O error, ENOMEM if out of memory.
  */
-int rwave_wopen(const char *fname, rwave_params_t *params, rwavew_t **rww)
+errno_t rwave_wopen(const char *fname, rwave_params_t *params, rwavew_t **rww)
 {
 	riff_wchunk_t fmt;
 	rwave_fmt_t rwfmt;
-	int rc;
+	errno_t rc;
 	rwavew_t *ww;
 
@@ -169,10 +169,10 @@
  *         not supported.
  */
-int rwave_write_samples(rwavew_t *ww, void *data, size_t bytes)
+errno_t rwave_write_samples(rwavew_t *ww, void *data, size_t bytes)
 {
 	size_t i;
 	uint16_t *d16, *b16;
 	size_t now;
-	int rc;
+	errno_t rc;
 
 	/* Convert sample data to little endian */
@@ -215,7 +215,7 @@
  *         anyway.
  */
-int rwave_wclose(rwavew_t *ww)
-{
-	int rc;
+errno_t rwave_wclose(rwavew_t *ww)
+{
+	errno_t rc;
 
 	rc = riff_wchunk_end(ww->rw, &ww->wave);
@@ -240,5 +240,5 @@
  * @return EOK on success, EIO on I/O error, ENOMEM if out of memory
  */
-int rwave_ropen(const char *fname, rwave_params_t *params, rwaver_t **rwr)
+errno_t rwave_ropen(const char *fname, rwave_params_t *params, rwaver_t **rwr)
 {
 	rwaver_t *wr = NULL;
@@ -247,5 +247,5 @@
 	rwave_fmt_t wfmt;
 	size_t nread;
-	int rc;
+	errno_t rc;
 
 	wr = calloc(1, sizeof(rwaver_t));
@@ -349,7 +349,7 @@
  *         EIO on I/O error.
  */
-int rwave_read_samples(rwaver_t *wr, void *buf, size_t bytes, size_t *nread)
-{
-	int rc;
+errno_t rwave_read_samples(rwaver_t *wr, void *buf, size_t bytes, size_t *nread)
+{
+	errno_t rc;
 
 	rc = riff_rchunk_read(wr->rr, &wr->data, buf, bytes, nread);
@@ -369,7 +369,7 @@
  *         anyway.
  */
-int rwave_rclose(rwaver_t *wr)
-{
-	int rc;
+errno_t rwave_rclose(rwaver_t *wr)
+{
+	errno_t rc;
 
 	rc = riff_rchunk_end(wr->rr, &wr->wave);