diff --git a/drivers/opp/of.c b/drivers/opp/of.c
index c02e20632fa6..9c4fd1f0e944 100644
--- a/drivers/opp/of.c
+++ b/drivers/opp/of.c
@@ -1039,7 +1039,7 @@ static int _of_add_opp_table_v1(struct device *dev, struct opp_table *opp_table)
 
 	val = prop->value;
 	while (nr) {
-		unsigned long freq = be32_to_cpup(val++) * 1000;
+		unsigned long freq = (unsigned long)be32_to_cpup(val++) * 1000;
 		unsigned long volt = be32_to_cpup(val++);
 		struct dev_pm_opp_data data = {
 			.freq = freq,