diff --git a/drivers/thermal/renesas/rzg3e_thermal.c b/drivers/thermal/renesas/rzg3e_thermal.c
index c44f5b8858d0..4acee4eaff05 100644
--- a/drivers/thermal/renesas/rzg3e_thermal.c
+++ b/drivers/thermal/renesas/rzg3e_thermal.c
@@ -194,7 +194,12 @@ static u16 rzg3e_thermal_temp_to_code(struct rzg3e_thermal_priv *priv, int temp_
 	s64 numerator, denominator;
 	s64 code;
 
-	numerator = (temp_mc - info->temp_d_mc) * (priv->trmval1 - priv->trmval0);
+	/*
+	 * Perform the arithmetic in 64 bits so that it cannot overflow for
+	 * -INT_MAX/INT_MAX values passed from the thermal core or when
+	 * userspace writes arbitrary trip point temperatures.
+	 */
+	numerator = ((s64)temp_mc - info->temp_d_mc) * (priv->trmval1 - priv->trmval0);
 	denominator = info->temp_e_mc - info->temp_d_mc;
 
 	code = div64_s64(numerator, denominator) + priv->trmval0;