diff --git a/src/basic/signal-util.c b/src/basic/signal-util.c
index c04f8be05b..331295c2c5 100644
--- a/src/basic/signal-util.c
+++ b/src/basic/signal-util.c
@@ -198,7 +198,7 @@ static const char *const __signal_table[] = {
 DEFINE_PRIVATE_STRING_TABLE_LOOKUP(__signal, int);
 
 const char *signal_to_string(int signo) {
-        static thread_local char buf[STRLEN("RTMIN+") + DECIMAL_STR_MAX(int) + 1];
+        static thread_local char buf[STRLEN("RTMIN+") + DECIMAL_STR_MAX(int)];
         const char *name;
 
         name = __signal_to_string(signo);