diff --git a/src/base.sol b/src/base.sol
index 4cf46d7..be41724 100644
--- a/src/base.sol
+++ b/src/base.sol
@@ -30,22 +30,24 @@ contract DSTokenBase is ERC20, DSMath {
         _supply = supply;
     }
 
-    function totalSupply() public view returns (uint) {
+    function totalSupply() public override view returns (uint) {
         return _supply;
     }
-    function balanceOf(address src) public view returns (uint) {
+    function balanceOf(address src) public override view returns (uint) {
         return _balances[src];
     }
-    function allowance(address src, address guy) public view returns (uint) {
+    function allowance(address src, address guy) public override view returns (uint) {
         return _approvals[src][guy];
     }
 
-    function transfer(address dst, uint wad) public returns (bool) {
+    function transfer(address dst, uint wad) public override returns (bool) {
         return transferFrom(msg.sender, dst, wad);
     }
 
     function transferFrom(address src, address dst, uint wad)
         public
+        override
+        virtual
         returns (bool)
     {
         if (src != msg.sender) {
@@ -62,7 +64,7 @@ contract DSTokenBase is ERC20, DSMath {
         return true;
     }
 
-    function approve(address guy, uint wad) public returns (bool) {
+    function approve(address guy, uint wad) public override virtual returns (bool) {
         _approvals[msg.sender][guy] = wad;
 
         emit Approval(msg.sender, guy, wad);
diff --git a/src/token.sol b/src/token.sol
index fb43edc..2f4217f 100644
--- a/src/token.sol
+++ b/src/token.sol
@@ -37,12 +37,13 @@ contract DSToken is DSTokenBase(0), DSStop {
         return super.approve(guy, uint(-1));
     }
 
-    function approve(address guy, uint wad) public stoppable returns (bool) {
+    function approve(address guy, uint wad) public override stoppable returns (bool) {
         return super.approve(guy, wad);
     }
 
     function transferFrom(address src, address dst, uint wad)
         public
+        override
         stoppable
         returns (bool)
     {