diff --git a/src/log.c b/src/log.c
index 053ef8450..0227a2a8c 100644
--- a/src/log.c
+++ b/src/log.c
@@ -5121,8 +5121,13 @@ int sess_build_logline_orig(struct session *sess, struct stream *s,
 
 			case LOG_FMT_UNIQUEID: // %ID
 				ret = NULL;
-				if (s)
+				if (s) {
+					/* if unique-id was not generated */
+					if (!isttest(s->unique_id) && !lf_expr_isempty(&sess->fe->format_unique_id)) {
+						stream_generate_unique_id(s, &sess->fe->format_unique_id);
+					}
 					ret = lf_text_len(tmplog, s->unique_id.ptr, s->unique_id.len, maxsize - (tmplog - dst), ctx);
+				}
 				else
 					ret = lf_text_len(tmplog, NULL, 0, maxsize - (tmplog - dst), ctx);
 				if (ret == NULL)
@@ -5218,10 +5223,6 @@ void do_log(struct session *sess, struct stream *s, struct log_orig origin)
 			}
 			level = s->logs.level - 1;
 		}
-		/* if unique-id was not generated */
-		if (!isttest(s->unique_id) && !lf_expr_isempty(&sess->fe->format_unique_id)) {
-			stream_generate_unique_id(s, &sess->fe->format_unique_id);
-		}
 	}
 
 	if (level == -1) {
@@ -5282,11 +5283,6 @@ void strm_log(struct stream *s, struct log_orig origin)
 			level = LOG_ERR;
 	}
 
-	/* if unique-id was not generated */
-	if (!isttest(s->unique_id) && !lf_expr_isempty(&sess->fe->format_unique_id)) {
-		stream_generate_unique_id(s, &sess->fe->format_unique_id);
-	}
-
 	if (!lf_expr_isempty(&sess->fe->logformat_sd)) {
 		sd_size = build_logline_orig(s, logline_rfc5424, global.max_syslog_len,
 		                             &sess->fe->logformat_sd, origin);