diff --git a/contracts/src/erc20/mod.rs b/contracts/src/erc20/mod.rs
index f9ee24016..deee4f06c 100644
--- a/contracts/src/erc20/mod.rs
+++ b/contracts/src/erc20/mod.rs
@@ -327,7 +327,11 @@ impl ERC20 {
             // `_total_supply` never overflows.
             // TODO: Think about SafeMath library
             let total_supply = self.total_supply();
-            self._total_supply.set(total_supply + value);
+            self._total_supply.set(
+                total_supply
+                    .checked_add(value)
+                    .expect("Should not exceed U256::MAX for `_total_supply"),
+            );
         } else {
             let from_balance = self._balances.get(from);
             if from_balance < value {