diff --git a/test/Collateral.t.sol b/test/Collateral.t.sol
index ceeb1993..6a2de040 100644
--- a/test/Collateral.t.sol
+++ b/test/Collateral.t.sol
@@ -254,8 +254,8 @@ contract DepositCollateral is CollateralTest {
     }
 
     function test_depositCollateral_ETH_Fuzz(uint256 amount) public {
-        /// @dev amount must be less than max MarketCollateralAmount
-        vm.assume(amount < 1_000_000_000_000_000_000_000);
+        /// @dev amount must be less than max MarketCollateralAmount - currentDepositedCollateral
+        vm.assume(amount < MAX_WRAPPABLE_AMOUNT);
         vm.assume(amount > SMALLEST_AMOUNT);
         vm.deal(ACTOR, amount);
 
@@ -520,7 +520,7 @@ contract WithdrawCollateral is CollateralTest {
         uint256 preBalance = ACTOR.balance;
 
         /// @dev amount must be less than max MarketCollateralAmount
-        vm.assume(amount < 1_000_000_000_000_000_000_000);
+        vm.assume(amount < MAX_WRAPPABLE_AMOUNT);
         vm.assume(amount > SMALLEST_AMOUNT);
         vm.deal(ACTOR, amount);
 
diff --git a/test/utils/Constants.sol b/test/utils/Constants.sol
index 96001427..72525084 100644
--- a/test/utils/Constants.sol
+++ b/test/utils/Constants.sol
@@ -62,6 +62,8 @@ contract Constants {
 
     uint256 internal constant SMALLEST_AMOUNT = 100 wei;
 
+    uint256 internal constant MAX_WRAPPABLE_AMOUNT = 900_000_000_000_000_000_000;
+
     address internal constant MARKET_CONFIGURATION_MODULE = address(0xC0FE);
 
     uint256 internal constant ZERO_CO_FEE = 0;