diff --git a/test/Collateral.test.js b/test/Collateral.test.js
index 2e6669c..8000a7e 100644
--- a/test/Collateral.test.js
+++ b/test/Collateral.test.js
@@ -1,5 +1,4 @@
 const { expect } = require("chai")
-const { exampleLock } = require("./examples")
 
 describe("Collateral", function () {
   let collateral, token
@@ -90,25 +89,4 @@ describe("Collateral", function () {
       expect(await collateral.balanceOf(account1.address)).to.equal(950)
     })
   })
-
-  describe("locking", function () {
-    let lock
-
-    beforeEach(async function () {
-      await token.approve(collateral.address, 42)
-      await collateral.deposit(42)
-      lock = await exampleLock()
-      await collateral.createLock(lock.id, lock.expiry)
-      await collateral.lock(account0.address, lock.id)
-    })
-
-    it("withdrawal fails when account is locked", async function () {
-      await expect(collateral.withdraw()).to.be.revertedWith("Account locked")
-    })
-
-    it("withdrawal succeeds when account is unlocked", async function () {
-      await collateral.unlock(lock.id)
-      await expect(collateral.withdraw()).not.to.be.reverted
-    })
-  })
 })
diff --git a/test/Marketplace.test.js b/test/Marketplace.test.js
index 9a27715..1302013 100644
--- a/test/Marketplace.test.js
+++ b/test/Marketplace.test.js
@@ -126,11 +126,6 @@ describe("Marketplace", function () {
         .withArgs(slot.request, slot.index, slotId(slot))
     })
 
-    it("locks collateral of host", async function () {
-      await marketplace.fillSlot(slot.request, slot.index, proof)
-      await expect(marketplace.withdraw()).to.be.revertedWith("Account locked")
-    })
-
     it("starts requiring storage proofs", async function () {
       await marketplace.fillSlot(slot.request, slot.index, proof)
       expect(await marketplace.proofEnd(slotId(slot))).to.be.gt(0)
@@ -535,6 +530,34 @@ describe("Marketplace", function () {
     })
   })
 
+  describe("collateral locking", function () {
+    beforeEach(async function () {
+      switchAccount(client)
+      await token.approve(marketplace.address, price(request))
+      await marketplace.requestStorage(request)
+      switchAccount(host)
+      await token.approve(marketplace.address, collateral)
+      await marketplace.deposit(collateral)
+    })
+
+    it("locks collateral of host when it fills a slot", async function () {
+      await marketplace.fillSlot(slot.request, slot.index, proof)
+      await expect(marketplace.withdraw()).to.be.revertedWith("Account locked")
+    })
+
+    it("allows withdrawal when all slots are free", async function () {
+      let slot1 = { ...slot, index: 0 }
+      let slot2 = { ...slot, index: 1 }
+      await marketplace.fillSlot(slot1.request, slot1.index, proof)
+      await marketplace.fillSlot(slot2.request, slot2.index, proof)
+      await waitUntilFinished(marketplace, requestId(request))
+      await marketplace.freeSlot(slotId(slot1))
+      await expect(marketplace.withdraw()).to.be.revertedWith("Account locked")
+      await marketplace.freeSlot(slotId(slot2))
+      await expect(marketplace.withdraw()).not.to.be.reverted
+    })
+  })
+
   describe("contract state", function () {
     beforeEach(async function () {
       switchAccount(client)