diff --git a/drivers/libusb1.c b/drivers/libusb1.c
index be7ebf72a7..8b2459c09e 100644
--- a/drivers/libusb1.c
+++ b/drivers/libusb1.c
@@ -730,8 +730,8 @@ static int nut_libusb_open(libusb_device_handle **udevp,
 #if (defined HAVE_PRAGMA_GCC_DIAGNOSTIC_PUSH_POP) && ( (defined HAVE_PRAGMA_GCC_DIAGNOSTIC_IGNORED_TYPE_LIMITS) || (defined HAVE_PRAGMA_GCC_DIAGNOSTIC_IGNORED_TAUTOLOGICAL_CONSTANT_OUT_OF_RANGE_COMPARE) || (defined HAVE_PRAGMA_GCC_DIAGNOSTIC_IGNORED_TAUTOLOGICAL_UNSIGNED_ZERO_COMPARE) )
 # pragma GCC diagnostic pop
 #endif
-			upsdebugx(2, "HID descriptor too long %d (max %d)",
-				rdlen, UINT16_MAX);
+			upsdebugx(2, "HID descriptor too long %d (max %" PRIuMAX ")",
+				rdlen, (uintmax_t)UINT16_MAX);
 			goto next_device;
 		}
 
diff --git a/drivers/nut-libfreeipmi.c b/drivers/nut-libfreeipmi.c
index 02f87b090c..8e37414772 100644
--- a/drivers/nut-libfreeipmi.c
+++ b/drivers/nut-libfreeipmi.c
@@ -230,7 +230,7 @@ int nut_ipmi_open(int ipmi_id, IPMIDevice_t *ipmi_dev)
 			if (area_length > (int)UINT8_MAX) {
 				libfreeipmi_cleanup();
 				fatal_with_errno(EXIT_FAILURE,
-					"nut_ipmi_open: got area_length %d is too large for libfreeipmi",
+					"nut_ipmi_open: got area_length %u is too large for libfreeipmi",
 					area_length);
 			}
 
@@ -794,7 +794,7 @@ static int libfreeipmi_get_sensors_info (IPMIDevice_t *ipmi_dev)
 		if (tmp_entity_id == entity_id
 			&& tmp_entity_instance == entity_instance)
 		{
-			upsdebugx (1, "Found record id = %u for device id %u",
+			upsdebugx (1, "Found record id = %u for device id %i",
 				record_id, ipmi_dev->ipmi_id);
 
 			/* Add it to the tracked list */
@@ -817,7 +817,7 @@ static int libfreeipmi_get_sensors_info (IPMIDevice_t *ipmi_dev)
 #endif /* HAVE_FREEIPMI_11X_12X */
 
 	if (ipmi_dev->sensors_count > INT_MAX) {
-		upsdebugx(1, "%s: Found %i sensors which is too many",
+		upsdebugx(1, "%s: Found %u sensors which is too many",
 			__func__, ipmi_dev->sensors_count);
 	}
 	return (int)ipmi_dev->sensors_count;
diff --git a/tools/nut-scanner/scan_ipmi.c b/tools/nut-scanner/scan_ipmi.c
index 0d40bfa63f..fb566480d9 100644
--- a/tools/nut-scanner/scan_ipmi.c
+++ b/tools/nut-scanner/scan_ipmi.c
@@ -617,13 +617,13 @@ nutscan_device_t * nutscan_scan_ipmi_device(const char * IPaddr, nutscan_ipmi_t
 			nut_dev->type = TYPE_IPMI;
 			nut_dev->driver = strdup(NUT_IPMI_DRV_NAME);
 			if (IPaddr == NULL) {
-				sprintf(port_id, "id%x", ipmi_id);
+				sprintf(port_id, "id%x", (unsigned int)ipmi_id);
 			}
 			else {
 				/* FIXME: also check against "localhost" and its IPv{4,6} */
 				/* FIXME: Should the IPv6 address here be bracketed?
 				 *  Does our driver support the notation? */
-				sprintf(port_id, "id%x@%s", ipmi_id, IPaddr);
+				sprintf(port_id, "id%x@%s", (unsigned int)ipmi_id, IPaddr);
 			}
 			nut_dev->port = strdup(port_id);
 			/* FIXME: also dump device.serial?
@@ -845,7 +845,7 @@ nutscan_device_t * nutscan_scan_ip_range_ipmi(nutscan_ip_range_list_t * irl, nut
 				upsdebugx(4, "%s: max_threads_scantype=%" PRIuSIZE
 					" curr_threads=%" PRIuSIZE
 					" thread_count=%" PRIuSIZE
-					" stwST=%d stwS=%d pass=%d",
+					" stwST=%d stwS=%d pass=%u",
 					__func__, max_threads_scantype,
 					curr_threads, thread_count,
 					stwST, stwS, pass