diff --git a/contracts/Shareable.sol b/contracts/Shareable.sol
index b73f31eee90..d416f80bec1 100644
--- a/contracts/Shareable.sol
+++ b/contracts/Shareable.sol
@@ -4,7 +4,7 @@ pragma solidity ^0.4.4;
 /*
  * Shareable
  *
- * Based on https://github.com/ethereum/dapp-bin/blob/master/wallet/wallet.sol 
+ * Based on https://github.com/ethereum/dapp-bin/blob/master/wallet/wallet.sol
  *
  * inheritable "property" contract that enables methods to be protected by requiring the acquiescence of either a single, or, crucially, each of a number of, designated owners.
  *
@@ -98,7 +98,7 @@ contract Shareable {
     return address(owners[ownerIndex + 1]);
   }
 
-  function isOwner(address _addr) returns (bool) {
+  function isOwner(address _addr) constant returns (bool) {
     return ownerIndex[uint(_addr)] > 0;
   }
 
@@ -162,4 +162,3 @@ contract Shareable {
   }
 
 }
-
diff --git a/contracts/test-helpers/ShareableMock.sol b/contracts/test-helpers/ShareableMock.sol
new file mode 100644
index 00000000000..ebf06546e0c
--- /dev/null
+++ b/contracts/test-helpers/ShareableMock.sol
@@ -0,0 +1,16 @@
+pragma solidity ^0.4.4;
+import "../Shareable.sol";
+
+contract ShareableMock is Shareable {
+
+  uint public count = 0;
+
+  function ShareableMock(address[] _owners, uint _required) Shareable(_owners, _required) {
+
+  }
+
+  function increaseCount(bytes32 action) onlymanyowners(action) {
+    count = count + 1;
+  }
+
+}
diff --git a/test/Shareable.js b/test/Shareable.js
new file mode 100644
index 00000000000..fba268268af
--- /dev/null
+++ b/test/Shareable.js
@@ -0,0 +1,101 @@
+contract('Shareable', function(accounts) {
+
+  it('should construct with correct owners and number of sigs required', async function() {
+    let requiredSigs = 2;
+    let owners = accounts.slice(1,4);
+    let shareable = await ShareableMock.new(owners, requiredSigs);
+
+    let required = await shareable.required();
+    assert.equal(required, requiredSigs);
+    let owner = await shareable.getOwner(0);
+    assert.equal(owner, accounts[0]);
+
+    for(let i = 0; i < accounts.length; i++) {
+      let owner = await shareable.getOwner(i);
+      let isowner = await shareable.isOwner(accounts[i]);
+      if(i <= owners.length) {
+        assert.equal(accounts[i], owner);
+        assert.isTrue(isowner);
+      } else {
+        assert.notEqual(accounts[i], owner);
+        assert.isFalse(isowner);
+      }
+    }
+  });
+
+  it('should only perform multisig function with enough sigs', async function() {
+    let requiredSigs = 3;
+    let owners = accounts.slice(1,4);
+    let shareable = await ShareableMock.new(owners, requiredSigs);
+    let hash = 1234;
+
+    let initCount = await shareable.count();
+    initCount = initCount.toString();
+
+    for(let i = 0; i < requiredSigs; i++) {
+      await shareable.increaseCount(hash, {from: accounts[i]});
+      let count = await shareable.count();
+      if(i == requiredSigs - 1) {
+        assert.equal(Number(initCount)+1, count.toString());
+      } else {
+        assert.equal(initCount, count.toString());
+      }
+    }
+  });
+
+  it('should require approval from different owners', async function() {
+    let requiredSigs = 2;
+    let owners = accounts.slice(1,4);
+    let shareable = await ShareableMock.new(owners, requiredSigs);
+    let hash = 1234;
+
+    let initCount = await shareable.count();
+    initCount = initCount.toString();
+
+    //Count shouldn't increase when the same owner calls repeatedly
+    for(let i = 0; i < 2; i++) {
+      await shareable.increaseCount(hash);
+      let count = await shareable.count();
+      assert.equal(initCount, count.toString());
+    }
+  });
+
+  it('should reset sig count after operation is approved', async function() {
+    let requiredSigs = 3;
+    let owners = accounts.slice(1,4);
+    let shareable = await ShareableMock.new(owners, requiredSigs);
+    let hash = 1234;
+
+    let initCount = await shareable.count();
+
+    for(let i = 0; i < requiredSigs * 3; i++) {
+      await shareable.increaseCount(hash, {from: accounts[i % 4]});
+      let count = await shareable.count();
+      if((i%(requiredSigs)) == requiredSigs - 1) {
+        initCount = Number(initCount)+1;
+        assert.equal(initCount, count);
+      } else {
+        assert.equal(initCount.toString(), count);
+      }
+    }
+  });
+
+  it('should not perform multisig function after an owner revokes', async function() {
+    let requiredSigs = 3;
+    let owners = accounts.slice(1,4);
+    let shareable = await ShareableMock.new(owners, requiredSigs);
+    let hash = 1234;
+
+    let initCount = await shareable.count();
+
+    for(let i = 0; i < requiredSigs; i++) {
+      if(i == 1) {
+        await shareable.revoke(hash, {from: accounts[i-1]});
+      }
+      await shareable.increaseCount(hash, {from: accounts[i]});
+      let count = await shareable.count();
+      assert.equal(initCount.toString(), count);
+    }
+  });
+
+});