diff --git a/contracts/zero-ex/contracts/src/features/IMigrate.sol b/contracts/zero-ex/contracts/src/features/IMigrate.sol
index 76c69a9501..99e46515e5 100644
--- a/contracts/zero-ex/contracts/src/features/IMigrate.sol
+++ b/contracts/zero-ex/contracts/src/features/IMigrate.sol
@@ -30,7 +30,7 @@ interface IMigrate {
 
     /// @dev Execute a migration function in the context of the ZeroEx contract.
     ///      The result of the function being called should be the magic bytes
-    ///      0x2c64c5ef. Only callable by the owner.
+    ///      0x2c64c5ef (`keccack('MIGRATE_SUCCESS')`). Only callable by the owner.
     ///      The owner will be temporarily set to `address(this)` inside the call.
     ///      The original owner can be retrieved through `getMigrationOwner()`.`
     /// @param target The migrator contract address.
diff --git a/contracts/zero-ex/contracts/src/features/Migrate.sol b/contracts/zero-ex/contracts/src/features/Migrate.sol
index f5ff916c19..8bbc20cd6c 100644
--- a/contracts/zero-ex/contracts/src/features/Migrate.sol
+++ b/contracts/zero-ex/contracts/src/features/Migrate.sol
@@ -55,7 +55,7 @@ contract Migrate is
 
     /// @dev Execute a migration function in the context of the ZeroEx contract.
     ///      The result of the function being called should be the magic bytes
-    ///      0x2c64c5ef. Only callable by the owner.
+    ///      0x2c64c5ef (`keccack('MIGRATE_SUCCESS')`). Only callable by the owner.
     ///      The owner will be temporarily set to `address(this)` inside the call.
     ///      The original owner can be retrieved through `getMigrationOwner()`.`
     /// @param target The migrator contract address.
diff --git a/contracts/zero-ex/contracts/src/migrations/LibBootstrap.sol b/contracts/zero-ex/contracts/src/migrations/LibBootstrap.sol
index e2a1744517..b5304441fc 100644
--- a/contracts/zero-ex/contracts/src/migrations/LibBootstrap.sol
+++ b/contracts/zero-ex/contracts/src/migrations/LibBootstrap.sol
@@ -26,6 +26,7 @@ import "../errors/LibProxyRichErrors.sol";
 library LibBootstrap {
 
     /// @dev Magic bytes returned by the bootstrapper to indicate success.
+    ///      This is `keccack('BOOTSTRAP_SUCCESS')`.
     bytes4 internal constant BOOTSTRAP_SUCCESS = 0xd150751b;
 
     /// @dev Perform a delegatecall and ensure it returns the magic bytes.
diff --git a/contracts/zero-ex/contracts/src/migrations/LibMigrate.sol b/contracts/zero-ex/contracts/src/migrations/LibMigrate.sol
index ebc71edc98..c994dfbdd7 100644
--- a/contracts/zero-ex/contracts/src/migrations/LibMigrate.sol
+++ b/contracts/zero-ex/contracts/src/migrations/LibMigrate.sol
@@ -26,6 +26,7 @@ import "../errors/LibMigrateRichErrors.sol";
 library LibMigrate {
 
     /// @dev Magic bytes returned by a migrator to indicate success.
+    ///      This is `keccack('MIGRATE_SUCCESS')`.
     bytes4 internal constant MIGRATE_SUCCESS = 0x2c64c5ef;
 
     /// @dev Perform a delegatecall and ensure it returns the magic bytes.
diff --git a/contracts/zero-ex/contracts/src/storage/LibStorage.sol b/contracts/zero-ex/contracts/src/storage/LibStorage.sol
index e494c652ff..403a1440c6 100644
--- a/contracts/zero-ex/contracts/src/storage/LibStorage.sol
+++ b/contracts/zero-ex/contracts/src/storage/LibStorage.sol
@@ -44,6 +44,9 @@ library LibStorage {
         pure
         returns (uint256 offset)
     {
+        // We don't use safeMul here to save gas.
+        // This should never overflow with a reasonable `STORAGE_OFFSET_MULTIPLIER`
+        // because Solidity will do a range check on `storageId` during the cast.
         return uint256(storageId) * STORAGE_OFFSET_MULTIPLIER;
     }
 }
diff --git a/contracts/zero-ex/test/storage_uniqueness_test.ts b/contracts/zero-ex/test/storage_uniqueness_test.ts
index f0e51d0c18..180433fa12 100644
--- a/contracts/zero-ex/test/storage_uniqueness_test.ts
+++ b/contracts/zero-ex/test/storage_uniqueness_test.ts
@@ -14,7 +14,7 @@ describe('Storage ID uniqueness test', () => {
         }
     }
 
-    it('all STORAGE_IDs are unique in storage libraries', async () => {
+    it('all StorageId references are unique in storage libraries', async () => {
         const sourcePaths = (await promisify(readdir)(STORAGE_SOURCES_DIR))
             .filter(p => p.endsWith('.sol'))
             .map(p => resolve(STORAGE_SOURCES_DIR, p));
@@ -26,7 +26,7 @@ describe('Storage ID uniqueness test', () => {
             for (let j = 0; j < storageIds.length; ++j) {
                 if (i !== j && storageId === storageIds[j]) {
                     throw new Error(
-                        `Found duplicate STORAGE_ID ${storageId} ` +
+                        `Found duplicate StorageId ${storageId} ` +
                             `in files ${basename(sourcePaths[i])}, ${basename(sourcePaths[j])}`,
                     );
                 }