diff --git a/contracts/libs/SetMap.sol b/contracts/libs/SetMap.sol
index bb34b59..8be47fb 100644
--- a/contracts/libs/SetMap.sol
+++ b/contracts/libs/SetMap.sol
@@ -279,7 +279,11 @@ library SetMap {
     internal
     returns (bool)
   {
-    return _set(map, key).add(value);
+    bool success = _set(map, key).add(value);
+    if (success) {
+      map._keys.add(Bytes32AddressSetMapKey.unwrap(key));
+    }
+    return success;
   }
 
   /// @notice Removes a single value from an Bytes32AddressSetMap
@@ -294,7 +298,12 @@ library SetMap {
     internal
     returns (bool)
   {
-    return _set(map, key).remove(value);
+    EnumerableSet.AddressSet storage set = _set(map, key);
+    bool success = _set(map, key).remove(value);
+    if (success && set.length() == 0) {
+      map._keys.remove(Bytes32AddressSetMapKey.unwrap(key));
+    }
+    return success;
   }
 
   /// @notice Clears values for a key.
diff --git a/contracts/libs/TestSetMap.sol b/contracts/libs/TestSetMap.sol
new file mode 100644
index 0000000..e232a93
--- /dev/null
+++ b/contracts/libs/TestSetMap.sol
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+import "./SetMap.sol";
+
+// exposes public functions for testing
+contract TestBytes32SetMap {
+  using SetMap for SetMap.Bytes32SetMap;
+
+  event OperationResult(bool result);
+
+  SetMap.Bytes32SetMap private _set;
+
+  function values(SetMap.Bytes32SetMapKey key,
+                  address addr)
+    public
+    view
+    returns (bytes32[] memory)
+  {
+    return _set.values(key, addr);
+  }
+
+  function add(SetMap.Bytes32SetMapKey key,
+               address addr,
+               bytes32 value)
+    public
+  {
+    bool result = _set.add(key, addr, value);
+    emit OperationResult(result);
+  }
+
+  function remove(SetMap.Bytes32SetMapKey key,
+                  address addr,
+                  bytes32 value)
+    public
+  {
+    bool result = _set.remove(key, addr, value);
+    emit OperationResult(result);
+  }
+
+  function clear(SetMap.Bytes32SetMapKey key)
+    public
+  {
+    _set.clear(key);
+  }
+
+  function length(SetMap.Bytes32SetMapKey key,
+                  address addr)
+    public
+    view
+    returns (uint256)
+  {
+    return _set.length(key, addr);
+  }
+}
+
+contract TestAddressBytes32SetMap {
+  using SetMap for SetMap.AddressBytes32SetMap;
+
+  event OperationResult(bool result);
+
+  SetMap.AddressBytes32SetMap private _set;
+
+  function values(SetMap.AddressBytes32SetMapKey key)
+    public
+    view
+    returns (bytes32[] memory)
+  {
+    return _set.values(key);
+  }
+
+  function add(SetMap.AddressBytes32SetMapKey key,
+               bytes32 value)
+    public
+  {
+    bool result = _set.add(key, value);
+    emit OperationResult(result);
+  }
+
+  function remove(SetMap.AddressBytes32SetMapKey key,
+                  bytes32 value)
+    public
+  {
+    bool result = _set.remove(key, value);
+    emit OperationResult(result);
+  }
+
+  function clear(SetMap.AddressBytes32SetMapKey key)
+    public
+  {
+    _set.clear(key);
+  }
+}
+
+contract TestBytes32AddressSetMap {
+  using EnumerableSet for EnumerableSet.Bytes32Set;
+  using SetMap for SetMap.Bytes32AddressSetMap;
+
+  event OperationResult(bool result);
+
+  SetMap.Bytes32AddressSetMap private _set;
+
+  function keys()
+    view
+    public
+    returns (bytes32[] memory)
+  {
+    return _set._keys.values();
+  }
+
+  function values(SetMap.Bytes32AddressSetMapKey key)
+    public
+    view
+    returns (address[] memory)
+  {
+    return _set.values(key);
+  }
+
+  function contains(SetMap.Bytes32AddressSetMapKey key,
+                    address addr)
+    public
+    view
+    returns (bool)
+  {
+    return _set.contains(key, addr);
+  }
+
+  function length(SetMap.Bytes32AddressSetMapKey key)
+    public
+    view
+    returns (uint256)
+  {
+    return _set.length(key);
+  }
+
+  function add(SetMap.Bytes32AddressSetMapKey key,
+               address value)
+    public
+  {
+    bool result = _set.add(key, value);
+    emit OperationResult(result);
+  }
+
+  function remove(SetMap.Bytes32AddressSetMapKey key,
+                  address value)
+    public
+  {
+    bool result = _set.remove(key, value);
+    emit OperationResult(result);
+  }
+
+  function clear(SetMap.Bytes32AddressSetMapKey key)
+    public
+  {
+    _set.clear(key);
+  }
+}
diff --git a/test/SetMap.test.js b/test/SetMap.test.js
new file mode 100644
index 0000000..d32469b
--- /dev/null
+++ b/test/SetMap.test.js
@@ -0,0 +1,198 @@
+const { ethers } = require("hardhat")
+const { expect } = require("chai")
+const { hexlify, randomBytes } = ethers.utils
+const { exampleAddress } = require("./examples")
+
+describe("SetMap", function () {
+  let account
+  let key
+  let value
+  let contract
+
+  describe("Bytes32SetMap", function () {
+    beforeEach(async function () {
+      let Bytes32SetMap = await ethers.getContractFactory("TestBytes32SetMap")
+      contract = await Bytes32SetMap.deploy()
+      ;[account] = await ethers.getSigners()
+      key = randomBytes(32)
+      value = randomBytes(32)
+    })
+
+    it("starts empty", async function () {
+      await expect(await contract.values(key, account.address)).to.deep.equal(
+        []
+      )
+    })
+
+    it("adds a key/address and value", async function () {
+      await expect(contract.add(key, account.address, value))
+        .to.emit(contract, "OperationResult")
+        .withArgs(true)
+      await expect(await contract.values(key, account.address)).to.deep.equal([
+        hexlify(value),
+      ])
+    })
+
+    it("removes a value for key/address", async function () {
+      let value1 = randomBytes(32)
+      await contract.add(key, account.address, value)
+      await contract.add(key, account.address, value1)
+      await expect(contract.remove(key, account.address, value))
+        .to.emit(contract, "OperationResult")
+        .withArgs(true)
+      await expect(await contract.values(key, account.address)).to.deep.equal([
+        hexlify(value1),
+      ])
+    })
+
+    it("clears all values for a key", async function () {
+      let key1 = randomBytes(32)
+      let value1 = randomBytes(32)
+      let value2 = randomBytes(32)
+      await contract.add(key, account.address, value)
+      await contract.add(key, account.address, value1)
+      await contract.add(key, account.address, value2)
+      await contract.add(key1, account.address, value)
+      await expect(contract.clear(key))
+      await expect(await contract.values(key, account.address)).to.deep.equal(
+        []
+      )
+      await expect(await contract.values(key1, account.address)).to.deep.equal([
+        hexlify(value),
+      ])
+    })
+
+    it("gets the length of values for a key/address", async function () {
+      let value1 = randomBytes(32)
+      let value2 = randomBytes(32)
+      await contract.add(key, account.address, value)
+      await contract.add(key, account.address, value1)
+      await contract.add(key, account.address, value2)
+      await expect(await contract.length(key, account.address)).to.equal(3)
+    })
+  })
+
+  describe("AddressBytes32SetMap", function () {
+    beforeEach(async function () {
+      let AddressBytes32SetMap = await ethers.getContractFactory(
+        "TestAddressBytes32SetMap"
+      )
+      contract = await AddressBytes32SetMap.deploy()
+      ;[account, account1] = await ethers.getSigners()
+      key = account.address
+      value = randomBytes(32)
+    })
+
+    it("starts empty", async function () {
+      await expect(await contract.values(key)).to.deep.equal([])
+    })
+
+    it("adds a key/address and value", async function () {
+      await expect(contract.add(key, value))
+        .to.emit(contract, "OperationResult")
+        .withArgs(true)
+      await expect(await contract.values(key)).to.deep.equal([hexlify(value)])
+    })
+
+    it("removes a value for key/address", async function () {
+      let value1 = randomBytes(32)
+      await contract.add(key, value)
+      await contract.add(key, value1)
+      await expect(contract.remove(key, value))
+        .to.emit(contract, "OperationResult")
+        .withArgs(true)
+      await expect(await contract.values(key)).to.deep.equal([hexlify(value1)])
+    })
+
+    it("clears all values for a key", async function () {
+      let key1 = account1.address
+      let value1 = randomBytes(32)
+      let value2 = randomBytes(32)
+      await contract.add(key, value)
+      await contract.add(key, value1)
+      await contract.add(key, value2)
+      await contract.add(key1, value)
+      await expect(contract.clear(key))
+      await expect(await contract.values(key)).to.deep.equal([])
+      await expect(await contract.values(key1)).to.deep.equal([hexlify(value)])
+    })
+  })
+
+  describe("Bytes32AddressSetMap", function () {
+    beforeEach(async function () {
+      let Bytes32AddressSetMap = await ethers.getContractFactory(
+        "TestBytes32AddressSetMap"
+      )
+      contract = await Bytes32AddressSetMap.deploy()
+      ;[account] = await ethers.getSigners()
+      key = randomBytes(32)
+      value = exampleAddress()
+    })
+
+    it("starts empty", async function () {
+      await expect(await contract.values(key)).to.deep.equal([])
+    })
+
+    it("adds a key/address and value", async function () {
+      await expect(contract.add(key, value))
+        .to.emit(contract, "OperationResult")
+        .withArgs(true)
+      await expect(await contract.values(key)).to.deep.equal([value])
+    })
+
+    it("returns list of keys", async function () {
+      let key1 = randomBytes(32)
+      let value1 = exampleAddress()
+      await contract.add(key, value)
+      await contract.add(key, value1)
+      await contract.add(key1, value)
+      await contract.add(key1, value1)
+      await expect(await contract.keys()).to.deep.equal([
+        hexlify(key),
+        hexlify(key1),
+      ])
+    })
+
+    it("contains a key/value pair", async function () {
+      let key1 = randomBytes(32)
+      let value1 = exampleAddress()
+      await contract.add(key, value)
+      await contract.add(key1, value1)
+      await expect(await contract.contains(key, value)).to.equal(true)
+      await expect(await contract.contains(key1, value1)).to.equal(true)
+      await expect(await contract.contains(key1, value)).to.equal(false)
+    })
+
+    it("removes a value for key/address", async function () {
+      let value1 = exampleAddress()
+      await contract.add(key, value)
+      await contract.add(key, value1)
+      await expect(contract.remove(key, value))
+        .to.emit(contract, "OperationResult")
+        .withArgs(true)
+      await expect(await contract.values(key)).to.deep.equal([value1])
+    })
+
+    it("clears all values for a key", async function () {
+      let key1 = randomBytes(32)
+      let value1 = exampleAddress()
+      let value2 = exampleAddress()
+      await contract.add(key, value)
+      await contract.add(key, value1)
+      await contract.add(key, value2)
+      await contract.add(key1, value)
+      await expect(contract.clear(key))
+      await expect(await contract.values(key)).to.deep.equal([])
+      await expect(await contract.values(key1)).to.deep.equal([value])
+    })
+
+    it("gets the length of values for a key/address", async function () {
+      let value1 = exampleAddress()
+      let value2 = exampleAddress()
+      await contract.add(key, value)
+      await contract.add(key, value1)
+      await contract.add(key, value2)
+      await expect(await contract.length(key)).to.equal(3)
+    })
+  })
+})
diff --git a/test/examples.js b/test/examples.js
index 1bc864a..50caa46 100644
--- a/test/examples.js
+++ b/test/examples.js
@@ -1,7 +1,7 @@
 const { ethers } = require("hardhat")
 const { hours } = require("./time")
 const { currentTime } = require("./evm")
-const { hexlify, randomBytes } = ethers.utils
+const { getAddress, hexlify, randomBytes } = ethers.utils
 
 const exampleRequest = async () => {
   const now = await currentTime()
@@ -37,5 +37,8 @@ const exampleLock = async () => {
     expiry: now + hours(1),
   }
 }
+const exampleAddress = () => {
+  return getAddress(hexlify(randomBytes(20)))
+}
 
-module.exports = { exampleRequest, exampleLock }
+module.exports = { exampleRequest, exampleLock, exampleAddress }