diff --git a/libnfc/buses/uart_posix.c b/libnfc/buses/uart_posix.c
index 4e41d8ec..3c7e6809 100644
--- a/libnfc/buses/uart_posix.c
+++ b/libnfc/buses/uart_posix.c
@@ -288,13 +288,13 @@ uart_receive (serial_port sp, uint8_t *pbtRx, const size_t szRx, void *abort_p,
     }
     // Read time-out
     if (res == 0) {
-      log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "Timeout!");
+      log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "%s", "Timeout!");
       return NFC_ETIMEOUT;
     }
 
     if (FD_ISSET (iAbortFd, &rfds)) {
       // Abort requested
-      log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "Abort!");
+      log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "%s", "Abort!");
       close (iAbortFd);
       return NFC_EOPABORTED;
     }
diff --git a/libnfc/chips/pn53x.c b/libnfc/chips/pn53x.c
index ee85a57a..a2ca897f 100644
--- a/libnfc/chips/pn53x.c
+++ b/libnfc/chips/pn53x.c
@@ -150,7 +150,7 @@ pn53x_transceive (struct nfc_device *pnd, const uint8_t *pbtTx, const size_t szT
   if (timeout > 0) {
     log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "Timeout values: %d", timeout);
   } else if (timeout == 0) {
-    log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "No timeout");
+    log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "%s", "No timeout");
   } else if (timeout == -1) {
     timeout = CHIP_DATA (pnd)->timeout_command;
   } else {
@@ -2547,12 +2547,12 @@ pn53x_check_ack_frame (struct nfc_device *pnd, const uint8_t *pbtRxFrame, const
 {
   if (szRxFrameLen >= sizeof (pn53x_ack_frame)) {
     if (0 == memcmp (pbtRxFrame, pn53x_ack_frame, sizeof (pn53x_ack_frame))) {
-      log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "PN53x ACKed");
+      log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "%s", "PN53x ACKed");
       return NFC_SUCCESS;
     }
   }
   pnd->last_error = NFC_EIO;
-  log_put (LOG_CATEGORY, NFC_PRIORITY_ERROR, "Unexpected PN53x reply!");
+  log_put (LOG_CATEGORY, NFC_PRIORITY_ERROR, "%s", "Unexpected PN53x reply!");
   return pnd->last_error;
 }
 
@@ -2561,7 +2561,7 @@ pn53x_check_error_frame (struct nfc_device *pnd, const uint8_t *pbtRxFrame, cons
 {
   if (szRxFrameLen >= sizeof (pn53x_error_frame)) {
     if (0 == memcmp (pbtRxFrame, pn53x_error_frame, sizeof (pn53x_error_frame))) {
-      log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "PN53x sent an error frame");
+      log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "%s", "PN53x sent an error frame");
       pnd->last_error = NFC_EIO;
       return pnd->last_error;
     }
@@ -2831,6 +2831,7 @@ pn53x_get_supported_baud_rate (nfc_device *pnd, const nfc_modulation_type nmt, n
     case NMT_DEP: 
       *supported_br = (nfc_baud_rate*)pn53x_dep_supported_baud_rates;
     break;
+    default:
     return NFC_EINVARG;
   }
   return NFC_SUCCESS;
diff --git a/libnfc/drivers/acr122s.c b/libnfc/drivers/acr122s.c
index cdb5a04e..f041bacf 100644
--- a/libnfc/drivers/acr122s.c
+++ b/libnfc/drivers/acr122s.c
@@ -476,7 +476,7 @@ acr122s_probe(nfc_connstring connstrings[], size_t connstrings_len, size_t *pszD
   (void) connstrings;
   (void) connstrings_len;
   *pszDeviceFound = 0;
-  log_put(LOG_CATEGORY, NFC_PRIORITY_INFO, "Serial auto-probing have been disabled at compile time. Skipping autoprobe.");
+  log_put(LOG_CATEGORY, NFC_PRIORITY_INFO, "%s", "Serial auto-probing have been disabled at compile time. Skipping autoprobe.");
   return false;
 #else /* SERIAL_AUTOPROBE_ENABLED */
   *pszDeviceFound = 0;
diff --git a/libnfc/drivers/arygon.c b/libnfc/drivers/arygon.c
index af9135ba..532b9ca4 100644
--- a/libnfc/drivers/arygon.c
+++ b/libnfc/drivers/arygon.c
@@ -101,7 +101,7 @@ arygon_probe (nfc_connstring connstrings[], size_t connstrings_len, size_t *pszD
   (void) connstrings;
   (void) connstrings_len;
   *pszDeviceFound = 0;
-  log_put (LOG_CATEGORY, NFC_PRIORITY_INFO, "Serial auto-probing have been disabled at compile time. Skipping autoprobe.");
+  log_put (LOG_CATEGORY, NFC_PRIORITY_INFO, "%s", "Serial auto-probing have been disabled at compile time. Skipping autoprobe.");
   return false;
 #else /* SERIAL_AUTOPROBE_ENABLED */
   *pszDeviceFound = 0;
@@ -113,7 +113,7 @@ arygon_probe (nfc_connstring connstrings[], size_t connstrings_len, size_t *pszD
 
   while ((acPort = acPorts[iDevice++])) {
     sp = uart_open (acPort);
-    log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "Trying to find ARYGON device on serial port: %s at %d bauds.", acPort, ARYGON_DEFAULT_SPEED);
+    log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "%s", "Trying to find ARYGON device on serial port: %s at %d bauds.", acPort, ARYGON_DEFAULT_SPEED);
 
     if ((sp != INVALID_SERIAL_PORT) && (sp != CLAIMED_SERIAL_PORT)) {
       // We need to flush input to be sure first reply does not comes from older byte transceive
@@ -344,7 +344,7 @@ arygon_tama_send (nfc_device *pnd, const uint8_t *pbtData, const size_t szData,
   if (pn53x_check_ack_frame (pnd, abtRxBuf, sizeof(abtRxBuf)) == 0) {
     // The PN53x is running the sent command
   } else if (0 == memcmp(arygon_error_unknown_mode, abtRxBuf, sizeof(abtRxBuf))) {
-    log_put (LOG_CATEGORY, NFC_PRIORITY_ERROR,  "Bad frame format." );
+    log_put (LOG_CATEGORY, NFC_PRIORITY_ERROR, "%s", "Bad frame format.");
     // We have already read 6 bytes and arygon_error_unknown_mode is 10 bytes long
     // so we have to read 4 remaining bytes to be synchronized at the next receiving pass.
     pnd->last_error = uart_receive (DRIVER_DATA (pnd)->port, abtRxBuf, 4, 0, timeout);
@@ -495,12 +495,12 @@ arygon_firmware (nfc_device *pnd, char *str)
 
   int res = uart_send (DRIVER_DATA (pnd)->port, arygon_firmware_version_cmd, sizeof (arygon_firmware_version_cmd), 0);
   if (res != 0) {
-    log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "Unable to send ARYGON firmware command.");
+    log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "%s", "Unable to send ARYGON firmware command.");
     return;
   }
   res = uart_receive (DRIVER_DATA (pnd)->port, abtRx, szRx, 0, 0);
   if (res != 0) {
-    log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "Unable to retrieve ARYGON firmware version.");
+    log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "%s", "Unable to retrieve ARYGON firmware version.");
     return;
   }
 
@@ -527,7 +527,7 @@ arygon_reset_tama (nfc_device *pnd)
   // or arygon_error_unknown_mode (ie. in case of the first byte was bad-transmitted)
   res = uart_receive (DRIVER_DATA (pnd)->port, abtRx, szRx, 0, 1000);
   if (res != 0) {
-    log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "No reply to 'reset TAMA' command.");
+    log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "%s", "No reply to 'reset TAMA' command.");
     pnd->last_error = res;
     return pnd->last_error;
   }
diff --git a/libnfc/drivers/pn53x_usb.c b/libnfc/drivers/pn53x_usb.c
index 8b94fdc6..a6dd8415 100644
--- a/libnfc/drivers/pn53x_usb.c
+++ b/libnfc/drivers/pn53x_usb.c
@@ -660,7 +660,7 @@ pn53x_usb_init (nfc_device *pnd)
   // ...and we don't care about error
   pnd->last_error = 0;
   if (SONY_RCS360 == DRIVER_DATA (pnd)->model) {
-    log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "SONY RC-S360 initialization.");
+    log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "%s", "SONY RC-S360 initialization.");
     const uint8_t abtCmd2[] = { 0x18, 0x01 };
     pn53x_transceive (pnd, abtCmd2, sizeof (abtCmd2), NULL, 0, 0);
     pn53x_usb_ack (pnd);
@@ -670,7 +670,7 @@ pn53x_usb_init (nfc_device *pnd)
     return res;
 
   if (ASK_LOGO == DRIVER_DATA (pnd)->model) {
-    log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "ASK LoGO initialization.");
+    log_put (LOG_CATEGORY, NFC_PRIORITY_TRACE, "%s", "ASK LoGO initialization.");
     /* Internal registers */
     /* Disable 100mA current limit, Power on Secure IC (SVDD) */
     pn53x_write_register (pnd, PN53X_REG_Control_switch_rng, 0xFF, SYMBOL_CURLIMOFF | SYMBOL_SIC_SWITCH_EN | SYMBOL_RANDOM_DATAREADY);
diff --git a/libnfc/log.h b/libnfc/log.h
index 6a41a079..879fbeb6 100644
--- a/libnfc/log.h
+++ b/libnfc/log.h
@@ -40,8 +40,8 @@
   #define NFC_PRIORITY_TRACE  "trace"
 #else
   // No logging
-  #define log_init() (0)
-  #define log_fini() (0)
+  #define log_init() ((void) 0)
+  #define log_fini() ((void) 0)
   #define log_msg(category, priority, message) do {} while (0)
   #define log_set_appender(category, appender) do {} while (0)
   #define log_put(category, priority, format, ...) do {} while (0)
diff --git a/libnfc/nfc.c b/libnfc/nfc.c
index c96f7440..43fa6248 100644
--- a/libnfc/nfc.c
+++ b/libnfc/nfc.c
@@ -106,20 +106,22 @@ const struct nfc_driver *nfc_drivers[] = {
  * This function must be called before calling any other libnfc function
  * @param context Optional output location for context pointer
  */
-void 
+void
 nfc_init(nfc_context *context)
 {
+  (void) context;
   log_init ();
 }
 
 /** @ingroup lib
  * @brief Deinitialize libnfc.
  * Should be called after closing all open devices and before your application terminates.
- *@param context The context to deinitialize 
+ *@param context The context to deinitialize
  */
-void  
+void
 nfc_exit(nfc_context *context)
 {
+  (void) context;
   log_fini ();
 }
 
@@ -176,6 +178,7 @@ nfc_get_default_device (nfc_connstring *connstring)
 nfc_device *
 nfc_open (nfc_context *context, const nfc_connstring connstring)
 {
+  (void) context;
   nfc_device *pnd = NULL;
 
   nfc_connstring ncs;
@@ -251,6 +254,8 @@ nfc_list_devices (nfc_context *context, nfc_connstring connstrings[] , size_t sz
   const struct nfc_driver *ndr;
   const struct nfc_driver **pndr = nfc_drivers;
 
+  (void) context;
+
   while ((ndr = *pndr)) {
     szN = 0;
     if (ndr->probe (connstrings + (szDeviceFound), szDevices - (szDeviceFound), &szN)) {
@@ -1028,4 +1033,4 @@ nfc_version (void)
 #else
   return PACKAGE_VERSION;
 #endif // SVN_REVISION
-}
\ No newline at end of file
+}
diff --git a/utils/nfc-probe.c b/utils/nfc-probe.c
index 95363983..8f8928fe 100644
--- a/utils/nfc-probe.c
+++ b/utils/nfc-probe.c
@@ -101,7 +101,7 @@ main (int argc, const char *argv[])
     printf ("No NFC device found.\n");
   }
 
-  printf ("%d NFC device(s) found:\n", szDeviceFound);
+  printf ("%d NFC device(s) found:\n", (int) szDeviceFound);
   for (i = 0; i < szDeviceFound; i++) {
     pnd = nfc_open (NULL, connstrings[i]);
     if (pnd != NULL) {