diff --git a/include/ecrt.h b/include/ecrt.h
index 82138d7f..754821f6 100644
--- a/include/ecrt.h
+++ b/include/ecrt.h
@@ -2262,8 +2262,9 @@ EC_PUBLIC_API int ecrt_soe_request_read(
  * change the header later on in realtime context.
  *
  * \ingroup ApplicationInterfaceRT
+ * \return 0 on success, otherwise negative error code.
  */
-EC_PUBLIC_API void ecrt_voe_handler_send_header(
+EC_PUBLIC_API int ecrt_voe_handler_send_header(
         ec_voe_handler_t *voe, /**< VoE handler. */
         uint32_t vendor_id, /**< Vendor ID. */
         uint16_t vendor_type /**< Vendor-specific type. */
@@ -2281,8 +2282,9 @@ EC_PUBLIC_API void ecrt_voe_handler_send_header(
  * activation).
  *
  * \ingroup ApplicationInterfaceRT
+ * \return 0 on success, otherwise negative error code.
  */
-EC_PUBLIC_API void ecrt_voe_handler_received_header(
+EC_PUBLIC_API int ecrt_voe_handler_received_header(
         const ec_voe_handler_t *voe, /**< VoE handler. */
         uint32_t *vendor_id, /**< Vendor ID. */
         uint16_t *vendor_type /**< Vendor-specific type. */
@@ -2339,8 +2341,9 @@ EC_PUBLIC_API size_t ecrt_voe_handler_data_size(
  * activation).
  *
  * \ingroup ApplicationInterfaceRT
+ * \return 0 on success, otherwise negative error code.
  */
-EC_PUBLIC_API void ecrt_voe_handler_write(
+EC_PUBLIC_API int ecrt_voe_handler_write(
         ec_voe_handler_t *voe, /**< VoE handler. */
         size_t size /**< Number of bytes to write (without the VoE header). */
         );
@@ -2364,8 +2367,9 @@ EC_PUBLIC_API void ecrt_voe_handler_write(
  * activation).
  *
  * \ingroup ApplicationInterfaceRT
+ * \return 0 on success, otherwise negative error code.
  */
-EC_PUBLIC_API void ecrt_voe_handler_read(
+EC_PUBLIC_API int ecrt_voe_handler_read(
         ec_voe_handler_t *voe /**< VoE handler. */
         );
 
@@ -2389,8 +2393,9 @@ EC_PUBLIC_API void ecrt_voe_handler_read(
  * activation).
  *
  * \ingroup ApplicationInterfaceRT
+ * \return 0 on success, otherwise negative error code.
  */
-EC_PUBLIC_API void ecrt_voe_handler_read_nosync(
+EC_PUBLIC_API int ecrt_voe_handler_read_nosync(
         ec_voe_handler_t *voe /**< VoE handler. */
         );
 
diff --git a/lib/voe_handler.c b/lib/voe_handler.c
index f0ae45c9..bc17c370 100644
--- a/lib/voe_handler.c
+++ b/lib/voe_handler.c
@@ -46,7 +46,7 @@ void ec_voe_handler_clear(ec_voe_handler_t *voe)
 
 /****************************************************************************/
 
-void ecrt_voe_handler_send_header(ec_voe_handler_t *voe, uint32_t vendor_id,
+int ecrt_voe_handler_send_header(ec_voe_handler_t *voe, uint32_t vendor_id,
         uint16_t vendor_type)
 {
     ec_ioctl_voe_t data;
@@ -59,14 +59,14 @@ void ecrt_voe_handler_send_header(ec_voe_handler_t *voe, uint32_t vendor_id,
 
     ret = ioctl(voe->config->master->fd, EC_IOCTL_VOE_SEND_HEADER, &data);
     if (EC_IOCTL_IS_ERROR(ret)) {
-        fprintf(stderr, "Failed to set VoE send header: %s\n",
-                strerror(EC_IOCTL_ERRNO(ret)));
+        return -EC_IOCTL_ERRNO(ret);
     }
+    return 0;
 }
 
 /****************************************************************************/
 
-void ecrt_voe_handler_received_header(const ec_voe_handler_t *voe,
+int ecrt_voe_handler_received_header(const ec_voe_handler_t *voe,
         uint32_t *vendor_id, uint16_t *vendor_type)
 {
     ec_ioctl_voe_t data;
@@ -79,9 +79,9 @@ void ecrt_voe_handler_received_header(const ec_voe_handler_t *voe,
 
     ret = ioctl(voe->config->master->fd, EC_IOCTL_VOE_REC_HEADER, &data);
     if (EC_IOCTL_IS_ERROR(ret)) {
-        fprintf(stderr, "Failed to get received VoE header: %s\n",
-                strerror(EC_IOCTL_ERRNO(ret)));
+        return -EC_IOCTL_ERRNO(ret);
     }
+    return 0;
 }
 
 /****************************************************************************/
@@ -100,7 +100,7 @@ size_t ecrt_voe_handler_data_size(const ec_voe_handler_t *voe)
 
 /****************************************************************************/
 
-void ecrt_voe_handler_read(ec_voe_handler_t *voe)
+int ecrt_voe_handler_read(ec_voe_handler_t *voe)
 {
     ec_ioctl_voe_t data;
     int ret;
@@ -110,14 +110,14 @@ void ecrt_voe_handler_read(ec_voe_handler_t *voe)
 
     ret = ioctl(voe->config->master->fd, EC_IOCTL_VOE_READ, &data);
     if (EC_IOCTL_IS_ERROR(ret)) {
-        fprintf(stderr, "Failed to initiate VoE reading: %s\n",
-                strerror(EC_IOCTL_ERRNO(ret)));
+        return -EC_IOCTL_ERRNO(ret);
     }
+    return 0;
 }
 
 /****************************************************************************/
 
-void ecrt_voe_handler_read_nosync(ec_voe_handler_t *voe)
+int ecrt_voe_handler_read_nosync(ec_voe_handler_t *voe)
 {
     ec_ioctl_voe_t data;
     int ret;
@@ -127,14 +127,14 @@ void ecrt_voe_handler_read_nosync(ec_voe_handler_t *voe)
 
     ret = ioctl(voe->config->master->fd, EC_IOCTL_VOE_READ_NOSYNC, &data);
     if (EC_IOCTL_IS_ERROR(ret)) {
-        fprintf(stderr, "Failed to initiate VoE reading: %s\n",
-                strerror(EC_IOCTL_ERRNO(ret)));
+        return -EC_IOCTL_ERRNO(ret);
     }
+    return 0;
 }
 
 /****************************************************************************/
 
-void ecrt_voe_handler_write(ec_voe_handler_t *voe, size_t size)
+int ecrt_voe_handler_write(ec_voe_handler_t *voe, size_t size)
 {
     ec_ioctl_voe_t data;
     int ret;
@@ -146,9 +146,9 @@ void ecrt_voe_handler_write(ec_voe_handler_t *voe, size_t size)
 
     ret = ioctl(voe->config->master->fd, EC_IOCTL_VOE_WRITE, &data);
     if (EC_IOCTL_IS_ERROR(ret)) {
-        fprintf(stderr, "Failed to initiate VoE writing: %s\n",
-                strerror(EC_IOCTL_ERRNO(ret)));
+        return -EC_IOCTL_ERRNO(ret);
     }
+    return 0;
 }
 
 /****************************************************************************/
diff --git a/master/ioctl.c b/master/ioctl.c
index 134b2edc..ed07d063 100644
--- a/master/ioctl.c
+++ b/master/ioctl.c
@@ -4139,8 +4139,7 @@ static ATTRIBUTES int ec_ioctl_voe_send_header(
         return -ENOENT;
     }
 
-    ecrt_voe_handler_send_header(voe, vendor_id, vendor_type);
-    return 0;
+    return ecrt_voe_handler_send_header(voe, vendor_id, vendor_type);
 }
 
 /****************************************************************************/
@@ -4160,6 +4159,7 @@ static ATTRIBUTES int ec_ioctl_voe_rec_header(
     ec_voe_handler_t *voe;
     uint32_t vendor_id;
     uint16_t vendor_type;
+    int ret;
 
     if (unlikely(!ctx->requested))
         return -EPERM;
@@ -4178,7 +4178,9 @@ static ATTRIBUTES int ec_ioctl_voe_rec_header(
         return -ENOENT;
     }
 
-    ecrt_voe_handler_received_header(voe, &vendor_id, &vendor_type);
+    ret = ecrt_voe_handler_received_header(voe, &vendor_id, &vendor_type);
+    if (ret)
+        return ret;
 
     if (likely(data.vendor_id))
         if (ec_copy_to_user(data.vendor_id, &vendor_id,
@@ -4226,8 +4228,7 @@ static ATTRIBUTES int ec_ioctl_voe_read(
         return -ENOENT;
     }
 
-    ecrt_voe_handler_read(voe);
-    return 0;
+    return ecrt_voe_handler_read(voe);
 }
 
 /****************************************************************************/
@@ -4263,8 +4264,7 @@ static ATTRIBUTES int ec_ioctl_voe_read_nosync(
         return -ENOENT;
     }
 
-    ecrt_voe_handler_read_nosync(voe);
-    return 0;
+    return ecrt_voe_handler_read_nosync(voe);
 }
 
 /****************************************************************************/
@@ -4309,8 +4309,7 @@ static ATTRIBUTES int ec_ioctl_voe_write(
             return -EFAULT;
     }
 
-    ecrt_voe_handler_write(voe, data.size);
-    return 0;
+    return ecrt_voe_handler_write(voe, data.size);
 }
 
 /****************************************************************************/
diff --git a/master/voe_handler.c b/master/voe_handler.c
index bc09069e..fc8cf307 100644
--- a/master/voe_handler.c
+++ b/master/voe_handler.c
@@ -112,16 +112,17 @@ size_t ec_voe_handler_mem_size(
  * Application interface.
  ****************************************************************************/
 
-void ecrt_voe_handler_send_header(ec_voe_handler_t *voe, uint32_t vendor_id,
+int ecrt_voe_handler_send_header(ec_voe_handler_t *voe, uint32_t vendor_id,
         uint16_t vendor_type)
 {
     voe->vendor_id = vendor_id;
     voe->vendor_type = vendor_type;
+    return 0;
 }
 
 /****************************************************************************/
 
-void ecrt_voe_handler_received_header(const ec_voe_handler_t *voe,
+int ecrt_voe_handler_received_header(const ec_voe_handler_t *voe,
         uint32_t *vendor_id, uint16_t *vendor_type)
 {
     uint8_t *header = voe->datagram.data + EC_MBOX_HEADER_SIZE;
@@ -130,6 +131,7 @@ void ecrt_voe_handler_received_header(const ec_voe_handler_t *voe,
         *vendor_id = EC_READ_U32(header);
     if (vendor_type)
         *vendor_type = EC_READ_U16(header + 4);
+    return 0;
 }
 
 /****************************************************************************/
@@ -148,30 +150,33 @@ size_t ecrt_voe_handler_data_size(const ec_voe_handler_t *voe)
 
 /****************************************************************************/
 
-void ecrt_voe_handler_read(ec_voe_handler_t *voe)
+int ecrt_voe_handler_read(ec_voe_handler_t *voe)
 {
     voe->dir = EC_DIR_INPUT;
     voe->state = ec_voe_handler_state_read_start;
     voe->request_state = EC_INT_REQUEST_BUSY;
+    return 0;
 }
 
 /****************************************************************************/
 
-void ecrt_voe_handler_read_nosync(ec_voe_handler_t *voe)
+int ecrt_voe_handler_read_nosync(ec_voe_handler_t *voe)
 {
     voe->dir = EC_DIR_INPUT;
     voe->state = ec_voe_handler_state_read_nosync_start;
     voe->request_state = EC_INT_REQUEST_BUSY;
+    return 0;
 }
 
 /****************************************************************************/
 
-void ecrt_voe_handler_write(ec_voe_handler_t *voe, size_t size)
+int ecrt_voe_handler_write(ec_voe_handler_t *voe, size_t size)
 {
     voe->dir = EC_DIR_OUTPUT;
     voe->data_size = size;
     voe->state = ec_voe_handler_state_write_start;
     voe->request_state = EC_INT_REQUEST_BUSY;
+    return 0;
 }
 
 /****************************************************************************/