diff --git a/src/event/ngx_event_quic_transport.c b/src/event/ngx_event_quic_transport.c
index 950b2ad3a..228a85e11 100644
--- a/src/event/ngx_event_quic_transport.c
+++ b/src/event/ngx_event_quic_transport.c
@@ -103,7 +103,7 @@ static char *ngx_quic_errors[] = {
     "INVALID_TOKEN",
     "APPLICATION_ERROR",
     "CRYPTO_BUFFER_EXCEEDED",
-    "unknown error 0xE",
+    "KEY_UPDATE_ERROR",
     "unknown error 0xF",
     "CRYPTO_ERROR",
 };
diff --git a/src/event/ngx_event_quic_transport.h b/src/event/ngx_event_quic_transport.h
index d85fd34bb..222f8ef51 100644
--- a/src/event/ngx_event_quic_transport.h
+++ b/src/event/ngx_event_quic_transport.h
@@ -89,7 +89,7 @@
 #define NGX_QUIC_ERR_INVALID_TOKEN                       0x0B
 #define NGX_QUIC_ERR_APPLICATION_ERROR                   0x0C
 #define NGX_QUIC_ERR_CRYPTO_BUFFER_EXCEEDED              0x0D
-/* 0xE is not defined */
+#define NGX_QUIC_ERR_KEY_UPDATE_ERROR                    0x0E
 /* 0xF is not defined */
 #define NGX_QUIC_ERR_CRYPTO_ERROR                        0x10