    function accrueDueTokens(address user) public {
        uint debt = debts[user];
        if(lastUpdated[user] == block.timestamp) return;
        uint accrued = (block.timestamp - lastUpdated[user]) * debt / 365 days;
        dueTokensAccrued[user] += accrued;
        totalDueTokensAccrued += accrued;
        lastUpdated[user] = block.timestamp;
        emit Transfer(user, address(0), accrued);
    }
accrued = (t_1 - t_0) * debt / 365 days
        = 12          * 1,000,000 / 31,536,000
        = 1,000,000 / 31,536,000
        = 0 (because unsigned integer division rounds down)
debt_max = 365 days / 12s -1 = 2,627,999
#loans = X / 2,627,999
#loans = 10^18 / 2,627,999 = 380517648599
#loans = 10^8 / 2,627,999 ~39
#loans ~= 49*10^8 / 2,627,999 ~= 1864
$ git diff src/test/DBR.t.sol
diff --git a/src/test/DBR.t.sol b/src/test/DBR.t.sol
index 3988cf7..8779da7 100644
--- a/src/test/DBR.t.sol
+++ b/src/test/DBR.t.sol
@@ -25,6 +25,20 @@ contract DBRTest is FiRMTest {
         vm.stopPrank();
     }
 
+    function testFail_free_borrow() public {
+        uint borrowAmount =  2_627_999;
+
+        vm.prank(address(market));
+        dbr.onBorrow(user, borrowAmount);
+
+        for (uint i = 12; i <= 3600; i += 12) {
+            vm.warp(block.timestamp + 12);
+            dbr.accrueDueTokens(user);
+        }
+        assertEq(dbr.deficitOf(user), 0);
+    }
+
+
     function testOnBorrow_Reverts_When_AccrueDueTokensBringsUserDbrBelow0() public {
         gibWeth(user, wethTestAmount);
         gibDBR(user, wethTestAmount);
$ forge test --match-test testFail_free_borrow -vv
[] Compiling...
[] Compiling 1 files with 0.8.17
[] Solc 0.8.17 finished in 2.62s
Compiler run successful

Running 1 test for src/test/DBR.t.sol:DBRTest
[FAIL. Reason: Assertion failed.] testFail_free_borrow() (gas: 1621543)
Test result: FAILED. 0 passed; 1 failed; finished in 8.03ms

Failing tests:
Encountered 1 failing test in src/test/DBR.t.sol:DBRTest
[FAIL. Reason: Assertion failed.] testFail_free_borrow() (gas: 1621543)

Encountered a total of 1 failing tests, 0 tests succeeded
