diff --git a/subsys/logging/log_minimal.c b/subsys/logging/log_minimal.c
index cfdc833ba09..3ebde8a691c 100644
--- a/subsys/logging/log_minimal.c
+++ b/subsys/logging/log_minimal.c
@@ -29,7 +29,7 @@ static void minimal_hexdump_line_print(const char *data, size_t length)
 {
 	for (size_t i = 0U; i < HEXDUMP_BYTES_IN_LINE; i++) {
 		if (i < length) {
-			printk("%02x ", data[i] & 0xFF);
+			printk("%02x ", (unsigned char)data[i] & 0xFFu);
 		} else {
 			printk("   ");
 		}