diff --git a/src/test/FeeOnTransferToken.sol b/src/test/FeeOnTransferToken.sol
index 90aba50..dfdccd1 100644
--- a/src/test/FeeOnTransferToken.sol
+++ b/src/test/FeeOnTransferToken.sol
@@ -166,7 +166,7 @@ contract FeeOnTransferToken {
                         INTERNAL MINT/BURN LOGIC
     //////////////////////////////////////////////////////////////*/
 
-    function _mint(address to, uint256 amount) internal virtual {
+    function mint(address to, uint256 amount) public virtual {
         totalSupply += amount;
 
         // Cannot overflow because the sum of all user
@@ -178,7 +178,7 @@ contract FeeOnTransferToken {
         emit Transfer(address(0), to, amount);
     }
 
-    function _burn(address from, uint256 amount) internal virtual {
+    function burn(address from, uint256 amount) public virtual {
         balanceOf[from] -= amount;
 
         // Cannot underflow because a user's balance
diff --git a/test/unit/Debit.t.sol b/test/unit/Debit.t.sol
index 89ab66c..f989bd6 100644
--- a/test/unit/Debit.t.sol
+++ b/test/unit/Debit.t.sol
@@ -5,18 +5,21 @@ import {Test} from "forge-std/Test.sol";
 import {MockERC20} from "solmate/test/utils/mocks/MockERC20.sol";
 import {FeeOnTransferToken} from "../../src/test/FeeOnTransferToken.sol";
 import {MockRMM} from "../MockRMM.sol";
+import {InsufficientPayment} from "./../../src/lib/RmmErrors.sol";
 
 contract DebitTest is Test {
     MockRMM rmm;
 
-    function test_debit_TransfersTokens() public {
+    function setUp() public {
         rmm = new MockRMM(address(0), "", "");
+    }
+
+    function test_debit_TransfersTokens() public {
         MockERC20 token = new MockERC20("", "", 18);
 
         uint256 amount = 1 ether;
 
         token.mint(address(this), amount);
-
         token.approve(address(rmm), amount);
 
         uint256 preBalanceRMM = token.balanceOf(address(rmm));
@@ -29,14 +32,12 @@ contract DebitTest is Test {
     }
 
     function test_debit_DownscalesAmount() public {
-        rmm = new MockRMM(address(0), "", "");
         MockERC20 token = new MockERC20("", "", 6);
 
         uint256 amountWAD = 1 ether;
         uint256 amountNative = 1 * 10 ** 6;
 
         token.mint(address(this), amountNative);
-
         token.approve(address(rmm), amountNative);
 
         uint256 preBalanceRMM = token.balanceOf(address(rmm));
@@ -47,4 +48,19 @@ contract DebitTest is Test {
         assertEq(token.balanceOf(address(rmm)), preBalanceRMM + amountNative);
         assertEq(token.balanceOf(address(this)), preBalanceUser - amountNative);
     }
+
+    function test_debit_RevertsInsufficientPayment() public {
+        FeeOnTransferToken token = new FeeOnTransferToken();
+
+        uint256 amount = 1 ether;
+
+        token.mint(address(this), amount);
+        token.approve(address(rmm), amount);
+
+        vm.expectRevert(
+            abi.encodeWithSelector(InsufficientPayment.selector, address(token), amount - token.transferFee(), amount)
+        );
+
+        rmm.debit(address(token), amount);
+    }
 }