diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 1557a20b6500..41a9bd52e1fd 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -2154,6 +2154,8 @@ static struct hist_field *parse_unary(struct hist_trigger_data *hist_data,
 		(HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS);
 	expr->fn = hist_field_unary_minus;
 	expr->operands[0] = operand1;
+	expr->size = operand1->size;
+	expr->is_signed = operand1->is_signed;
 	expr->operator = FIELD_OP_UNARY_MINUS;
 	expr->name = expr_str(expr, 0);
 	expr->type = kstrdup(operand1->type, GFP_KERNEL);
@@ -2293,6 +2295,7 @@ static struct hist_field *parse_expr(struct hist_trigger_data *hist_data,
 
 	/* The operand sizes should be the same, so just pick one */
 	expr->size = operand1->size;
+	expr->is_signed = operand1->is_signed;
 
 	expr->operator = field_op;
 	expr->name = expr_str(expr, 0);