diff --git a/contracts/ExponentialStaking.sol b/contracts/ExponentialStaking.sol
index 63fbecff..dd765b7a 100644
--- a/contracts/ExponentialStaking.sol
+++ b/contracts/ExponentialStaking.sol
@@ -16,7 +16,7 @@ import {RewardsSource} from "./RewardsSource.sol";
 /// The balance received for staking (and thus the voting power and rewards
 /// distribution) goes up exponentially by the end of the staked period.
 contract ExponentialStaking is ERC20Votes {
-    uint256 public immutable epoch; // timestamp
+    uint256 public immutable epoch; // Start of staking program - timestamp
     ERC20 public immutable asset; // Must not allow reentrancy
     RewardsSource public immutable rewardsSource;
     uint256 public immutable minStakeDuration; // in seconds
@@ -136,7 +136,8 @@ contract ExponentialStaking is ERC20Votes {
 
         // Update or create lockup
         if (lockupId != NEW_STAKE) {
-            require(newEnd > oldEnd, "Staking: New lockup must be longer");
+            require(newEnd >= oldEnd, "Staking: New lockup must not be shorter");
+            require(newPoints > oldPoints, "Staking: Must have increased amount or duration");
             lockups[to][uint256(lockupId)] = lockup;
         } else {
             lockups[to].push(lockup);
diff --git a/tests/staking/ExponentialStaking.t.sol b/tests/staking/ExponentialStaking.t.sol
index 4bbb2be0..83b4adf1 100644
--- a/tests/staking/ExponentialStaking.t.sol
+++ b/tests/staking/ExponentialStaking.t.sol
@@ -186,7 +186,7 @@ contract ExponentialStakingTest is Test {
 
         vm.startPrank(bob);
         staking.stake(100 ether, 11 days, bob, false, NEW_STAKE);
-        vm.expectRevert("Staking: New lockup must be longer");
+        vm.expectRevert("Staking: New lockup must not be shorter");
         staking.stake(1 ether, 8 days, bob, false, 0);
     }