diff --git a/contracts/zero-ex/contracts/src/storage/LibOwnableStorage.sol b/contracts/zero-ex/contracts/src/storage/LibOwnableStorage.sol
index 641c9b4ed4..811109acfc 100644
--- a/contracts/zero-ex/contracts/src/storage/LibOwnableStorage.sol
+++ b/contracts/zero-ex/contracts/src/storage/LibOwnableStorage.sol
@@ -33,9 +33,9 @@ library LibOwnableStorage {
 
     /// @dev Get the storage bucket for this contract.
     function getStorage() internal pure returns (Storage storage stor) {
-        uint256 storageOffset = LibStorage.getStorageOffset(
+        uint256 storageSlot = LibStorage.getStorageSlot(
             LibStorage.StorageId.Ownable
         );
-        assembly { stor_slot := storageOffset }
+        assembly { stor_slot := storageSlot }
     }
 }
diff --git a/contracts/zero-ex/contracts/src/storage/LibProxyStorage.sol b/contracts/zero-ex/contracts/src/storage/LibProxyStorage.sol
index c13817eb80..2a37a9439d 100644
--- a/contracts/zero-ex/contracts/src/storage/LibProxyStorage.sol
+++ b/contracts/zero-ex/contracts/src/storage/LibProxyStorage.sol
@@ -33,9 +33,9 @@ library LibProxyStorage {
 
     /// @dev Get the storage bucket for this contract.
     function getStorage() internal pure returns (Storage storage stor) {
-        uint256 storageOffset = LibStorage.getStorageOffset(
+        uint256 storageSlot = LibStorage.getStorageSlot(
             LibStorage.StorageId.Proxy
         );
-        assembly { stor_slot := storageOffset }
+        assembly { stor_slot := storageSlot }
     }
 }
diff --git a/contracts/zero-ex/contracts/src/storage/LibSimpleFunctionRegistryStorage.sol b/contracts/zero-ex/contracts/src/storage/LibSimpleFunctionRegistryStorage.sol
index 27dd52fb54..9b536a018d 100644
--- a/contracts/zero-ex/contracts/src/storage/LibSimpleFunctionRegistryStorage.sol
+++ b/contracts/zero-ex/contracts/src/storage/LibSimpleFunctionRegistryStorage.sol
@@ -33,9 +33,9 @@ library LibSimpleFunctionRegistryStorage {
 
     /// @dev Get the storage bucket for this contract.
     function getStorage() internal pure returns (Storage storage stor) {
-        uint256 storageOffset = LibStorage.getStorageOffset(
+        uint256 storageSlot = LibStorage.getStorageSlot(
             LibStorage.StorageId.SimpleFunctionRegistry
         );
-        assembly { stor_slot := storageOffset }
+        assembly { stor_slot := storageSlot }
     }
 }
diff --git a/contracts/zero-ex/contracts/src/storage/LibStorage.sol b/contracts/zero-ex/contracts/src/storage/LibStorage.sol
index edcd92e1f1..e6ae3bbd6d 100644
--- a/contracts/zero-ex/contracts/src/storage/LibStorage.sol
+++ b/contracts/zero-ex/contracts/src/storage/LibStorage.sol
@@ -23,29 +23,29 @@ pragma experimental ABIEncoderV2;
 /// @dev Common storage helpers
 library LibStorage {
 
-    /// @dev What to multiply a storage ID by to get its offset.
-    ///      This is also the maximum number of fields inside a storage
-    ///      bucket.
-    uint256 internal constant STORAGE_OFFSET_MULTIPLIER = 1e18;
+    /// @dev What to bit-shift a storage ID by to get its slot.
+    ///      This gives us a maximum of 2**128 inline fields in each bucket.
+    uint256 private constant STORAGE_SLOT_EXP = 128;
 
     /// @dev Storage IDs for feature storage buckets.
     enum StorageId {
-        Unused, // Unused buffer for state accidents.
         Proxy,
         SimpleFunctionRegistry,
         Ownable
     }
 
-    /// @dev Get the storage offset given a storage ID.
+    /// @dev Get the storage slot given a storage ID. We assign unique, well-spaced
+    ///     slots to storage bucket variables to ensure they do not overlap.
+    ///     See: https://solidity.readthedocs.io/en/v0.6.6/assembly.html#access-to-external-variables-functions-and-libraries
     /// @param storageId An entry in `StorageId`
-    /// @return offset The storage offset.
-    function getStorageOffset(StorageId storageId)
+    /// @return slot The storage slot.
+    function getStorageSlot(StorageId storageId)
         internal
         pure
-        returns (uint256 offset)
+        returns (uint256 slot)
     {
-        // This should never overflow with a reasonable `STORAGE_OFFSET_MULTIPLIER`
+        // This should never overflow with a reasonable `STORAGE_SLOT_EXP`
         // because Solidity will do a range check on `storageId` during the cast.
-        return uint256(storageId) * STORAGE_OFFSET_MULTIPLIER;
+        return (uint256(storageId) + 1) << STORAGE_SLOT_EXP;
     }
 }