diff --git a/Changes b/Changes
index 29dd6942e..578d5056c 100644
--- a/Changes
+++ b/Changes
@@ -2346,3 +2346,4 @@
 - Make default service stamp 0 (zero) again, instead of '*' which was
   introduced by ESVID changes a few days ago. This makes anope happy,
   and also means nothing will change in a non-ESVID scenario.
+- Fix misuse of stdarg.h macros when calling vsyslog() (#4065 by Jimini).
diff --git a/src/s_extra.c b/src/s_extra.c
index 54cccb16a..1af111b22 100644
--- a/src/s_extra.c
+++ b/src/s_extra.c
@@ -293,6 +293,8 @@ void ircd_log(int flags, char *format, ...)
 #ifdef HAVE_SYSLOG
 		if (!stricmp(logs->file, "syslog") && logs->flags & flags) {
 #ifdef HAVE_VSYSLOG
+			va_end(ap);
+			va_start(ap, format);
 			vsyslog(LOG_INFO, format, ap);
 #else
 			/* %s just to be safe */