diff --git a/include/types/proxy.h b/include/types/proxy.h
index 290b02d5c..fa640edb5 100644
--- a/include/types/proxy.h
+++ b/include/types/proxy.h
@@ -79,7 +79,7 @@ enum pr_mode {
 /* unused: 0x04, 0x08, 0x10 */
 #define PR_O_PREF_LAST  0x00000020      /* prefer last server */
 #define PR_O_DISPATCH   0x00000040      /* use dispatch mode */
-/* unused: 0x00000080 */
+#define PR_O_FORCED_ID  0x00000080      /* proxy's ID was forced in the configuration */
 #define PR_O_FWDFOR     0x00000100      /* conditionally insert x-forwarded-for with client address */
 #define PR_O_IGNORE_PRB 0x00000200      /* ignore empty requests (aborts and timeouts) */
 #define PR_O_NULLNOLOG  0x00000400      /* a connect without request will not be logged */
diff --git a/src/cfgparse.c b/src/cfgparse.c
index cf3c0931b..1403bd19d 100644
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -2613,6 +2613,7 @@ int cfg_parse_listen(const char *file, int linenum, char **args, int kwm)
 
 		curproxy->uuid = atol(args[1]);
 		curproxy->conf.id.key = curproxy->uuid;
+		curproxy->options |= PR_O_FORCED_ID;
 
 		if (curproxy->uuid <= 0) {
 			Alert("parsing [%s:%d]: custom id has to be > 0.\n",