diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 6a9fa34e2785ccf3e7d9e745dddc63e67955e655..1475d7347fe0c10aac810a9de0c9a0d387361524 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -2581,7 +2581,8 @@ static struct hist_field *parse_expr(struct hist_trigger_data *hist_data,
 	operand1_str = str;
 	str = sep+1;
 
-	if (!operand1_str || !str)
+	/* Binary operator requires both operands */
+	if (*operand1_str == '\0' || *str == '\0')
 		goto free;
 
 	operand_flags = 0;