diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index abd4fa5d3088..87494c7c619d 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -2457,7 +2457,7 @@ static int arg_num_eval(struct tep_print_arg *arg, long long *val)
 static char *arg_eval (struct tep_print_arg *arg)
 {
 	long long val;
-	static char buf[20];
+	static char buf[24];
 
 	switch (arg->type) {
 	case TEP_PRINT_ATOM: