diff --git a/CHANGES b/CHANGES
index 7b52587617..8c096d37f9 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+4312.	[bug]		dig's unknown dns and edns flags (MBZ value) logging
+			was not consistent. [RT #41600]
+
 4311.	[bug]		Prevent "rndc delzone" from being used on
 			response-policy zones. [RT #41593]
 
diff --git a/lib/dns/message.c b/lib/dns/message.c
index 7fdee4e795..bc7df345ce 100644
--- a/lib/dns/message.c
+++ b/lib/dns/message.c
@@ -3254,7 +3254,7 @@ dns_message_pseudosectiontotext(dns_message_t *msg,
 		mbz &= ~DNS_MESSAGEEXTFLAG_DO;		/* Known Flags. */
 		if (mbz != 0) {
 			ADD_STRING(target, "; MBZ: ");
-			snprintf(buf, sizeof(buf), "%.4x ", mbz);
+			snprintf(buf, sizeof(buf), "0x%.4x", mbz);
 			ADD_STRING(target, buf);
 			ADD_STRING(target, ", udp: ");
 		} else