diff --git a/src/core/lib/BasicOrderFulfiller.sol b/src/core/lib/BasicOrderFulfiller.sol
index d0a3ffe..a673cfc 100644
--- a/src/core/lib/BasicOrderFulfiller.sol
+++ b/src/core/lib/BasicOrderFulfiller.sol
@@ -91,6 +91,9 @@ import {
     OrderFulfilled_offer_body_offset,
     OrderFulfilled_offer_head_offset,
     OrderFulfilled_offer_length_baseOffset,
+    OrderFulfilled_offer_length_baseOffset_relativeTo_OrderFulfilled_baseOffset,
+    OrderFulfilled_offer_itemType_baseOffset_relativeTo_OrderFulfilled_baseOffset,
+    OrderFulfilled_offer_token_baseOffset_relativeTo_OrderFulfilled_baseOffset,
     OrderFulfilled_post_memory_region_reservedBytes,
     OrderFulfilled_selector,
     ReceivedItem_amount_offset,
@@ -1006,16 +1009,31 @@ contract BasicOrderFulfiller is OrderValidator {
             )
 
             // Set a length of 1 for the offer array.
-            mstore(add(eventDataPtr, 0x80), 1)
+            mstore(
+                add(
+                    eventDataPtr,
+                    OrderFulfilled_offer_length_baseOffset_relativeTo_OrderFulfilled_baseOffset
+                ),
+                1
+            )
 
             // Write itemType to the SpentItem struct.
-            mstore(add(eventDataPtr, 0xa0), offeredItemType)
+            mstore(
+                add(
+                    eventDataPtr,
+                    OrderFulfilled_offer_itemType_baseOffset_relativeTo_OrderFulfilled_baseOffset
+                ),
+                offeredItemType
+            )
 
             // Copy calldata region with (offerToken, offerIdentifier,
             // offerAmount) from OrderParameters to (token, identifier,
             // amount) in SpentItem struct.
             calldatacopy(
-                add(eventDataPtr, 0xc0),
+                add(
+                    eventDataPtr,
+                    OrderFulfilled_offer_token_baseOffset_relativeTo_OrderFulfilled_baseOffset
+                ),
                 BasicOrder_offerToken_cdPtr,
                 ThreeWords
             )
diff --git a/src/core/lib/OrderValidator.sol b/src/core/lib/OrderValidator.sol
index b8dcf06..4582318 100644
--- a/src/core/lib/OrderValidator.sol
+++ b/src/core/lib/OrderValidator.sol
@@ -111,25 +111,27 @@ contract OrderValidator is Executor, ZoneInteraction {
             _runTimeConstantTrue() // Signifies to revert if order is invalid.
         );
 
-        // If the order is not already validated, verify the supplied signature.
-        if (!orderStatus.isValidated) {
-            _verifySignature(
-                offerer, 
-                orderHash,
-                _toBytesReturnType(_decodeBytes)(
-                    // Wrap the absolute pointer to the order signature as a
-                    // CalldataPointer.
-                    CalldataPointer.wrap(
-                        // Read the relative pointer to the order signature.
-                        CalldataPointer
-                            .wrap(BasicOrder_signature_cdPtr)
-                            .readMaskedUint256() +
-                            // Add the BasicOrderParameters struct offset to the
-                            // relative pointer.
-                            BasicOrder_basicOrderParameters_cd_offset
+        unchecked {
+            // If the order is not already validated, verify the supplied signature.
+            if (!orderStatus.isValidated) {
+                _verifySignature(
+                    offerer,
+                    orderHash,
+                    _toBytesReturnType(_decodeBytes)(
+                        // Wrap the absolute pointer to the order signature as a
+                        // CalldataPointer.
+                        CalldataPointer.wrap(
+                            // Read the relative pointer to the order signature.
+                            CalldataPointer
+                                .wrap(BasicOrder_signature_cdPtr)
+                                .readMaskedUint256() +
+                                // Add the BasicOrderParameters struct offset to the
+                                // relative pointer.
+                                BasicOrder_basicOrderParameters_cd_offset
+                        )
                     )
-                )
-            );
+                );
+            }
         }
     }
 
diff --git a/src/types/lib/ConsiderationConstants.sol b/src/types/lib/ConsiderationConstants.sol
index 7cc70f3..6f80468 100644
--- a/src/types/lib/ConsiderationConstants.sol
+++ b/src/types/lib/ConsiderationConstants.sol
@@ -288,6 +288,10 @@ uint256 constant OrderFulfilled_baseOffset = 0x180;
 uint256 constant OrderFulfilled_consideration_length_baseOffset = 0x2a0;
 uint256 constant OrderFulfilled_offer_length_baseOffset = 0x200;
 
+uint256 constant OrderFulfilled_offer_length_baseOffset_relativeTo_OrderFulfilled_baseOffset = 0x80;
+uint256 constant OrderFulfilled_offer_itemType_baseOffset_relativeTo_OrderFulfilled_baseOffset = 0xa0;
+uint256 constant OrderFulfilled_offer_token_baseOffset_relativeTo_OrderFulfilled_baseOffset = 0xc0;
+
 // Related constants used for restricted order checks on basic orders.
 uint256 constant OrderFulfilled_baseDataSize = 0x160;
 // uint256 constant ValidateOrder_offerDataOffset = 0x184;
@@ -314,10 +318,10 @@ uint256 constant OrderFulfilled_post_memory_region_reservedBytes = 0x60;
  * pointing to the `OrderFulfilled`'s spent item array's length memory
  * position then we would have:
  *
- * ptr - 0x0180 : padded calldata selector 
+ * ptr - 0x0180 : zero-padded calldata selector
  * ptr - 0x0160 : ZoneParameter's struct head (0x20)
  * ptr - 0x0140 : order hash
- * ptr - 0x0120 : fulfiller / msg.sender
+ * ptr - 0x0120 : fulfiller (msg.sender)
  * ptr - 0x0100 : offerer 
  * ptr - 0x00e0 : spent items' head
  * ptr - 0x00c0 : received items' head 
@@ -326,7 +330,7 @@ uint256 constant OrderFulfilled_post_memory_region_reservedBytes = 0x60;
  * ptr - 0x0060 : start time
  * ptr - 0x0040 : end time
  * ptr - 0x0020 : zone hash
- * ptr - 0x0000: offer.length (1)
+ * ptr - 0x0000 : offer.length (1)
  * ...
  *
  * Note that the padded calldata selector will be at minimum at the