diff --git a/package.json b/package.json
index 31aa650..fd3a704 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@garmin/fitsdk",
-  "version": "21.178.0",
+  "version": "21.188.0",
   "description": "FIT JavaScript SDK",
   "main": "src/index.js",
   "type": "module",
diff --git a/src/accumulator.js b/src/accumulator.js
index 2032c10..8dbe3e1 100644
--- a/src/accumulator.js
+++ b/src/accumulator.js
@@ -5,8 +5,8 @@
 // Transfer (FIT) Protocol License.
 /////////////////////////////////////////////////////////////////////////////////////////////
 // ****WARNING****  This file is auto-generated!  Do NOT edit this file.
-// Profile Version = 21.178.0Release
-// Tag = production/release/21.178.0-0-g3bea629
+// Profile Version = 21.188.0Release
+// Tag = production/release/21.188.0-0-g55050f8
 /////////////////////////////////////////////////////////////////////////////////////////////
 
 
diff --git a/src/bit-stream.js b/src/bit-stream.js
index cddb035..b95c670 100644
--- a/src/bit-stream.js
+++ b/src/bit-stream.js
@@ -5,8 +5,8 @@
 // Transfer (FIT) Protocol License.
 /////////////////////////////////////////////////////////////////////////////////////////////
 // ****WARNING****  This file is auto-generated!  Do NOT edit this file.
-// Profile Version = 21.178.0Release
-// Tag = production/release/21.178.0-0-g3bea629
+// Profile Version = 21.188.0Release
+// Tag = production/release/21.188.0-0-g55050f8
 /////////////////////////////////////////////////////////////////////////////////////////////
 
 
diff --git a/src/crc-calculator.js b/src/crc-calculator.js
index 252b6b7..810561d 100644
--- a/src/crc-calculator.js
+++ b/src/crc-calculator.js
@@ -5,8 +5,8 @@
 // Transfer (FIT) Protocol License.
 /////////////////////////////////////////////////////////////////////////////////////////////
 // ****WARNING****  This file is auto-generated!  Do NOT edit this file.
-// Profile Version = 21.178.0Release
-// Tag = production/release/21.178.0-0-g3bea629
+// Profile Version = 21.188.0Release
+// Tag = production/release/21.188.0-0-g55050f8
 /////////////////////////////////////////////////////////////////////////////////////////////
 
 
diff --git a/src/decoder.js b/src/decoder.js
index 5e5f96d..088f8a0 100644
--- a/src/decoder.js
+++ b/src/decoder.js
@@ -5,8 +5,8 @@
 // Transfer (FIT) Protocol License.
 /////////////////////////////////////////////////////////////////////////////////////////////
 // ****WARNING****  This file is auto-generated!  Do NOT edit this file.
-// Profile Version = 21.178.0Release
-// Tag = production/release/21.178.0-0-g3bea629
+// Profile Version = 21.188.0Release
+// Tag = production/release/21.188.0-0-g55050f8
 /////////////////////////////////////////////////////////////////////////////////////////////
 
 
@@ -30,6 +30,7 @@ const LOCAL_MESG_NUM_MASK = 0x0F;
 const HEADER_WITH_CRC_SIZE = 14;
 const HEADER_WITHOUT_CRC_SIZE = 12;
 const CRC_SIZE = 2;
+const PROFILE_VERSION_SCALE_CHANGE_VALUE = 2199;
 
 const DecodeMode = Object.freeze({
     NORMAL: "normal",
@@ -43,6 +44,7 @@ class Decoder {
     #stream = null;
     #accumulator = new Accumulator();
     #messages = {};
+    #profileVersion = null;
     #fieldsWithSubFields = [];
     #fieldsToExpand = [];
 
@@ -200,7 +202,7 @@ class Decoder {
         mergeHeartRates = true,
         decodeMemoGlobs = false,
         skipHeader = false,
-        dataOnly = false,} = {}) {
+        dataOnly = false, } = {}) {
 
         this.#mesgListener = mesgListener;
         this.#mesgDefinitionListener = mesgDefinitionListener;
@@ -217,6 +219,7 @@ class Decoder {
         this.#localMessageDefinitions = [];
         this.#developerDataDefinitions = {};
         this.#messages = {};
+        this.#profileVersion = null;
 
         const errors = [];
 
@@ -247,7 +250,7 @@ class Decoder {
             errors.push(error);
         }
         finally {
-            return { messages: this.#messages, errors: errors };
+            return { messages: this.#messages, profileVersion: this.#profileVersion, errors: errors };
         }
     }
 
@@ -260,7 +263,8 @@ class Decoder {
 
         this.#stream.crcCalculator = new CrcCalculator();
 
-        const { headerSize, dataSize } = Decoder.#readFileHeader(this.#stream, { decodeMode: this.#decodeMode });
+        const { headerSize, dataSize, profileVersion, } = Decoder.#readFileHeader(this.#stream, { decodeMode: this.#decodeMode });
+        this.#profileVersion ??= profileVersion;
 
         // Read data messages and definitions
         while (this.#stream.position < (position + headerSize + dataSize)) {
@@ -313,7 +317,7 @@ class Decoder {
             const fieldDefinition = {
                 fieldDefinitionNumber: this.#stream.readByte(),
                 size: this.#stream.readByte(),
-                baseType: this.#stream.readByte()
+                baseType: this.#stream.readByte() & FIT.BaseTypeMask,
             };
 
             if (!(fieldDefinition.baseType in FIT.BaseTypeDefinitions)) {
@@ -515,7 +519,7 @@ class Decoder {
         this.#developerDataDefinitions[message.developerDataIndex.rawFieldValue].fields.push({
             developerDataIndex: message.developerDataIndex?.rawFieldValue,
             fieldDefinitionNumber: message.fieldDefinitionNumber?.rawFieldValue,
-            fitBaseTypeId: message.fitBaseTypeId?.rawFieldValue ?? null,
+            fitBaseTypeId: message.fitBaseTypeId?.rawFieldValue & FIT.BaseTypeMask ?? null,
             fieldName: message.fieldName?.rawFieldValue ?? null,
             array: message.array?.rawFieldValue ?? null,
             components: message.components?.rawFieldValue ?? null,
@@ -799,26 +803,27 @@ class Decoder {
     static #readFileHeader(stream, { resetPosition = false, decodeMode = DecodeMode.NORMAL }) {
         const position = stream.position;
 
-        if(decodeMode !== DecodeMode.NORMAL) {
-            if(decodeMode === DecodeMode.SKIP_HEADER) {
+        if (decodeMode !== DecodeMode.NORMAL) {
+            if (decodeMode === DecodeMode.SKIP_HEADER) {
                 stream.seek(HEADER_WITH_CRC_SIZE);
             }
 
             const headerSize = decodeMode === DecodeMode.SKIP_HEADER ? HEADER_WITH_CRC_SIZE : 0;
+            const dataSize = stream.length - headerSize - CRC_SIZE;
 
             return {
                 headerSize,
-                dataSize:  stream.length - headerSize - CRC_SIZE,
+                dataSize,
             };
         }
 
         const fileHeader = {
             headerSize: stream.readByte(),
             protocolVersion: stream.readByte(),
-            profileVersion: stream.readUInt16(),
+            profileVersion: this.#expandProfileVersion(stream.readUInt16()),
             dataSize: stream.readUInt32(),
             dataType: stream.readString(4),
-            headerCRC: 0
+            headerCRC: null
         };
 
         if (fileHeader.headerSize === 14) {
@@ -835,6 +840,14 @@ class Decoder {
     #throwError(error = "") {
         throw Error(`FIT Runtime Error at byte ${this.#stream.position} ${error}`.trimEnd());
     }
+
+    static #expandProfileVersion = (profileVersion) => {
+        const scale = profileVersion > PROFILE_VERSION_SCALE_CHANGE_VALUE ? 1000 : 100
+        return {
+            major: Math.floor(profileVersion / scale),
+            minor: profileVersion % scale
+        }
+    }
 }
 
 export default Decoder;
\ No newline at end of file
diff --git a/src/encoder.js b/src/encoder.js
index 0bd6c8d..732e291 100644
--- a/src/encoder.js
+++ b/src/encoder.js
@@ -5,8 +5,8 @@
 // Transfer (FIT) Protocol License.
 /////////////////////////////////////////////////////////////////////////////////////////////
 // ****WARNING****  This file is auto-generated!  Do NOT edit this file.
-// Profile Version = 21.178.0Release
-// Tag = production/release/21.178.0-0-g3bea629
+// Profile Version = 21.188.0Release
+// Tag = production/release/21.188.0-0-g55050f8
 /////////////////////////////////////////////////////////////////////////////////////////////
 
 
diff --git a/src/fit.js b/src/fit.js
index efb6f1e..fa63ba9 100644
--- a/src/fit.js
+++ b/src/fit.js
@@ -5,8 +5,8 @@
 // Transfer (FIT) Protocol License.
 /////////////////////////////////////////////////////////////////////////////////////////////
 // ****WARNING****  This file is auto-generated!  Do NOT edit this file.
-// Profile Version = 21.178.0Release
-// Tag = production/release/21.178.0-0-g3bea629
+// Profile Version = 21.188.0Release
+// Tag = production/release/21.188.0-0-g55050f8
 /////////////////////////////////////////////////////////////////////////////////////////////
 
 
@@ -17,40 +17,42 @@ const BaseType = {
     ENUM: 0x00,
     SINT8: 0x01,
     UINT8: 0x02,
-    SINT16: 0x83,
-    UINT16: 0x84,
-    SINT32: 0x85,
-    UINT32: 0x86,
+    SINT16: 0x03,
+    UINT16: 0x04,
+    SINT32: 0x05,
+    UINT32: 0x06,
     STRING: 0x07,
-    FLOAT32: 0x88,
-    FLOAT64: 0x89,
+    FLOAT32: 0x08,
+    FLOAT64: 0x09,
     UINT8Z: 0x0A,
-    UINT16Z: 0x8B,
-    UINT32Z: 0x8C,
+    UINT16Z: 0x0B,
+    UINT32Z: 0x0C,
     BYTE: 0x0D,
-    SINT64: 0x8E,
-    UINT64: 0x8F,
-    UINT64Z: 0x90
+    SINT64: 0x0E,
+    UINT64: 0x0F,
+    UINT64Z: 0x10
 };
 
+const BaseTypeMask = 0x1F;
+
 const BaseTypeDefinitions = {
-    0x00: { size: 1, type: BaseType.ENUM, invalid: 0xFF },
-    0x01: { size: 1, type: BaseType.SINT8, invalid: 0x7F },
-    0x02: { size: 1, type: BaseType.UINT8, invalid: 0xFF },
-    0x83: { size: 2, type: BaseType.SINT16, invalid: 0x7FFF },
-    0x84: { size: 2, type: BaseType.UINT16, invalid: 0xFFFF },
-    0x85: { size: 4, type: BaseType.SINT32, invalid: 0x7FFFFFFF },
-    0x86: { size: 4, type: BaseType.UINT32, invalid: 0xFFFFFFFF },
-    0x07: { size: 1, type: BaseType.STRING, invalid: 0x00 },
-    0x88: { size: 4, type: BaseType.FLOAT32, invalid: 0xFFFFFFFF },
-    0x89: { size: 8, type: BaseType.FLOAT64, invalid: 0xFFFFFFFFFFFFFFFF },
-    0x0A: { size: 1, type: BaseType.UINT8Z, invalid: 0x00 },
-    0x8B: { size: 2, type: BaseType.UINT16Z, invalid: 0x0000 },
-    0x8C: { size: 4, type: BaseType.UINT32Z, invalid: 0x00000000 },
-    0x0D: { size: 1, type: BaseType.BYTE, invalid: 0xFF },
-    0x8E: { size: 8, type: BaseType.SINT64, invalid: 0x7FFFFFFFFFFFFFFF },
-    0x8F: { size: 8, type: BaseType.UINT64, invalid: 0xFFFFFFFFFFFFFFFF },
-    0x90: { size: 8, type: BaseType.UINT64Z, invalid: 0x0000000000000000 },
+    0x00: { size: 1, type: BaseType.ENUM, baseTypeEndianFlag: 0x00, invalid: 0xFF },
+    0x01: { size: 1, type: BaseType.SINT8, baseTypeEndianFlag: 0x00, invalid: 0x7F },
+    0x02: { size: 1, type: BaseType.UINT8, baseTypeEndianFlag: 0x00, invalid: 0xFF },
+    0x03: { size: 2, type: BaseType.SINT16, baseTypeEndianFlag: 0x80, invalid: 0x7FFF },
+    0x04: { size: 2, type: BaseType.UINT16, baseTypeEndianFlag: 0x80, invalid: 0xFFFF },
+    0x05: { size: 4, type: BaseType.SINT32, baseTypeEndianFlag: 0x80, invalid: 0x7FFFFFFF },
+    0x06: { size: 4, type: BaseType.UINT32, baseTypeEndianFlag: 0x80, invalid: 0xFFFFFFFF },
+    0x07: { size: 1, type: BaseType.STRING, baseTypeEndianFlag: 0x00, invalid: 0x00 },
+    0x08: { size: 4, type: BaseType.FLOAT32, baseTypeEndianFlag: 0x80, invalid: 0xFFFFFFFF },
+    0x09: { size: 8, type: BaseType.FLOAT64, baseTypeEndianFlag: 0x80, invalid: 0xFFFFFFFFFFFFFFFF },
+    0x0A: { size: 1, type: BaseType.UINT8Z, baseTypeEndianFlag: 0x00, invalid: 0x00 },
+    0x0B: { size: 2, type: BaseType.UINT16Z, baseTypeEndianFlag: 0x80, invalid: 0x0000 },
+    0x0C: { size: 4, type: BaseType.UINT32Z, baseTypeEndianFlag: 0x80, invalid: 0x00000000 },
+    0x0D: { size: 1, type: BaseType.BYTE, baseTypeEndianFlag: 0x00, invalid: 0xFF },
+    0x0E: { size: 8, type: BaseType.SINT64, baseTypeEndianFlag: 0x80, invalid: 0x7FFFFFFFFFFFFFFF },
+    0x0F: { size: 8, type: BaseType.UINT64, baseTypeEndianFlag: 0x80, invalid: 0xFFFFFFFFFFFFFFFF },
+    0x10: { size: 8, type: BaseType.UINT64Z, baseTypeEndianFlag: 0x80, invalid: 0x0000000000000000 },
 };
 
 const NumericFieldTypes = [
@@ -158,6 +160,7 @@ const isNumberStringDateOrBoolean = (obj) => {
 
 export default {
     BaseType,
+    BaseTypeMask,
     BaseTypeDefinitions,
     NumericFieldTypes,
     FloatingPointFieldTypes,
diff --git a/src/index.js b/src/index.js
index 9913ce5..c9d4c85 100644
--- a/src/index.js
+++ b/src/index.js
@@ -5,8 +5,8 @@
 // Transfer (FIT) Protocol License.
 /////////////////////////////////////////////////////////////////////////////////////////////
 // ****WARNING****  This file is auto-generated!  Do NOT edit this file.
-// Profile Version = 21.178.0Release
-// Tag = production/release/21.178.0-0-g3bea629
+// Profile Version = 21.188.0Release
+// Tag = production/release/21.188.0-0-g55050f8
 /////////////////////////////////////////////////////////////////////////////////////////////
 
 
diff --git a/src/mesg-definition.js b/src/mesg-definition.js
index 5a342e5..ce751da 100644
--- a/src/mesg-definition.js
+++ b/src/mesg-definition.js
@@ -5,8 +5,8 @@
 // Transfer (FIT) Protocol License.
 /////////////////////////////////////////////////////////////////////////////////////////////
 // ****WARNING****  This file is auto-generated!  Do NOT edit this file.
-// Profile Version = 21.178.0Release
-// Tag = production/release/21.178.0-0-g3bea629
+// Profile Version = 21.188.0Release
+// Tag = production/release/21.188.0-0-g55050f8
 /////////////////////////////////////////////////////////////////////////////////////////////
 
 
@@ -67,6 +67,7 @@ class MesgDefinition {
                     num: fieldProfile[1].num,
                     size: this.#fieldSize(mesg[fieldName], baseTypeDef),
                     baseType: baseType,
+                    baseTypeEndianFlag: baseTypeDef.baseTypeEndianFlag,
                     type: fieldProfile[1].type,
                     scale,
                     offset,
@@ -77,11 +78,11 @@ class MesgDefinition {
             Object.keys(mesg.developerFields ?? {})?.sort()?.forEach((key) => {
                 const { developerDataIdMesg, fieldDescriptionMesg, } = this.#fieldDescriptionForKey(fieldDescriptions, key);
 
-                const baseTypeDef = FIT.BaseTypeDefinitions[fieldDescriptionMesg.fitBaseTypeId];
+                const baseTypeDef = FIT.BaseTypeDefinitions[fieldDescriptionMesg.fitBaseTypeId & FIT.BaseTypeMask];
 
                 this.developerFieldDefinitions.push({
                     key,
-                    baseType: fieldDescriptionMesg.fitBaseTypeId,
+                    baseType: fieldDescriptionMesg.fitBaseTypeId & FIT.BaseTypeMask,
                     fieldDefinitionNumber: fieldDescriptionMesg.fieldDefinitionNumber,
                     size: this.#fieldSize(mesg.developerFields[key], baseTypeDef),
                     developerDataIndex: developerDataIdMesg.developerDataIndex,
@@ -137,7 +138,7 @@ class MesgDefinition {
         this.fieldDefinitions.forEach((fieldDefinition) => {
             outputStream.writeUInt8(fieldDefinition.num);
             outputStream.writeUInt8(fieldDefinition.size);
-            outputStream.writeUInt8(fieldDefinition.baseType);
+            outputStream.writeUInt8(fieldDefinition.baseType | fieldDefinition.baseTypeEndianFlag);
         });
 
         // Developer Field Definitions
diff --git a/src/output-stream.js b/src/output-stream.js
index 7b6efe7..cb6a934 100644
--- a/src/output-stream.js
+++ b/src/output-stream.js
@@ -5,8 +5,8 @@
 // Transfer (FIT) Protocol License.
 /////////////////////////////////////////////////////////////////////////////////////////////
 // ****WARNING****  This file is auto-generated!  Do NOT edit this file.
-// Profile Version = 21.178.0Release
-// Tag = production/release/21.178.0-0-g3bea629
+// Profile Version = 21.188.0Release
+// Tag = production/release/21.188.0-0-g55050f8
 /////////////////////////////////////////////////////////////////////////////////////////////
 
 
diff --git a/src/profile.js b/src/profile.js
index ce67945..038ade5 100644
--- a/src/profile.js
+++ b/src/profile.js
@@ -5,15 +5,15 @@
 // Transfer (FIT) Protocol License.
 /////////////////////////////////////////////////////////////////////////////////////////////
 // ****WARNING****  This file is auto-generated!  Do NOT edit this file.
-// Profile Version = 21.178.0Release
-// Tag = production/release/21.178.0-0-g3bea629
+// Profile Version = 21.188.0Release
+// Tag = production/release/21.188.0-0-g55050f8
 /////////////////////////////////////////////////////////////////////////////////////////////
 
 
 const Profile = {
     version: {
         major: 21,
-        minor: 178,
+        minor: 188,
         patch: 0,
         type: "Release"
     },
@@ -4763,7 +4763,7 @@ const Profile = {
                     subFields: []
             },
             253: {
-                num: 253, // Sesson end time.
+                num: 253,
                 name: "timestamp",
                 type: "dateTime",
                 baseType: "uint32",
@@ -7170,7 +7170,7 @@ const Profile = {
                     subFields: []
             },
             253: {
-                num: 253, // Lap end time.
+                num: 253,
                 name: "timestamp",
                 type: "dateTime",
                 baseType: "uint32",
@@ -15771,7 +15771,7 @@ const Profile = {
                     subFields: []
             },
             253: {
-                num: 253, // Lap end time.
+                num: 253,
                 name: "timestamp",
                 type: "dateTime",
                 baseType: "uint32",
@@ -24796,6 +24796,7 @@ types: {
        4446: "hrmFit",
        4472: "marqGen2Commander",
        4477: "lilyAthlete", // aka the Lily 2 Active
+       4525: "rallyX10", // Rally 110/210
        4532: "fenix8Solar",
        4533: "fenix8SolarLarge",
        4534: "fenix8Small",
@@ -24811,13 +24812,22 @@ types: {
        4603: "venuX1",
        4606: "hrm200",
        4625: "vivoactive6",
+       4631: "fenix8Pro",
+       4633: "edge550",
+       4634: "edge850",
+       4643: "venu4",
+       4644: "venu4s",
        4647: "approachS44",
        4655: "edgeMtb",
        4656: "approachS50",
        4666: "fenixE",
+       4745: "bounce2",
        4759: "instinct3Solar50mm",
        4775: "tactix8Amoled",
        4776: "tactix8Solar",
+       4879: "d2Mach2",
+       4678: "instinctCrossoverAmoled",
+       4944: "d2AirX15",
        10007: "sdm4", // SDM4 footpod
        10014: "edgeRemote",
        20533: "tacxTrainingAppWin",
diff --git a/src/stream.js b/src/stream.js
index 1f9fede..5f7ba6f 100644
--- a/src/stream.js
+++ b/src/stream.js
@@ -5,8 +5,8 @@
 // Transfer (FIT) Protocol License.
 /////////////////////////////////////////////////////////////////////////////////////////////
 // ****WARNING****  This file is auto-generated!  Do NOT edit this file.
-// Profile Version = 21.178.0Release
-// Tag = production/release/21.178.0-0-g3bea629
+// Profile Version = 21.188.0Release
+// Tag = production/release/21.188.0-0-g55050f8
 /////////////////////////////////////////////////////////////////////////////////////////////
 
 
diff --git a/src/utils-hr-mesg.js b/src/utils-hr-mesg.js
index 4406de6..d5effbb 100644
--- a/src/utils-hr-mesg.js
+++ b/src/utils-hr-mesg.js
@@ -5,8 +5,8 @@
 // Transfer (FIT) Protocol License.
 /////////////////////////////////////////////////////////////////////////////////////////////
 // ****WARNING****  This file is auto-generated!  Do NOT edit this file.
-// Profile Version = 21.178.0Release
-// Tag = production/release/21.178.0-0-g3bea629
+// Profile Version = 21.188.0Release
+// Tag = production/release/21.188.0-0-g55050f8
 /////////////////////////////////////////////////////////////////////////////////////////////
 
 
diff --git a/src/utils-internal.js b/src/utils-internal.js
index f348db0..81ce703 100644
--- a/src/utils-internal.js
+++ b/src/utils-internal.js
@@ -5,8 +5,8 @@
 // Transfer (FIT) Protocol License.
 /////////////////////////////////////////////////////////////////////////////////////////////
 // ****WARNING****  This file is auto-generated!  Do NOT edit this file.
-// Profile Version = 21.178.0Release
-// Tag = production/release/21.178.0-0-g3bea629
+// Profile Version = 21.188.0Release
+// Tag = production/release/21.188.0-0-g55050f8
 /////////////////////////////////////////////////////////////////////////////////////////////
 
 
diff --git a/src/utils-memo-glob.js b/src/utils-memo-glob.js
index e3876ce..27516e7 100644
--- a/src/utils-memo-glob.js
+++ b/src/utils-memo-glob.js
@@ -5,8 +5,8 @@
 // Transfer (FIT) Protocol License.
 /////////////////////////////////////////////////////////////////////////////////////////////
 // ****WARNING****  This file is auto-generated!  Do NOT edit this file.
-// Profile Version = 21.178.0Release
-// Tag = production/release/21.178.0-0-g3bea629
+// Profile Version = 21.188.0Release
+// Tag = production/release/21.188.0-0-g55050f8
 /////////////////////////////////////////////////////////////////////////////////////////////
 
 import Profile from "./profile.js";
diff --git a/src/utils.js b/src/utils.js
index fc391f1..27df85e 100644
--- a/src/utils.js
+++ b/src/utils.js
@@ -5,8 +5,8 @@
 // Transfer (FIT) Protocol License.
 /////////////////////////////////////////////////////////////////////////////////////////////
 // ****WARNING****  This file is auto-generated!  Do NOT edit this file.
-// Profile Version = 21.178.0Release
-// Tag = production/release/21.178.0-0-g3bea629
+// Profile Version = 21.188.0Release
+// Tag = production/release/21.188.0-0-g55050f8
 /////////////////////////////////////////////////////////////////////////////////////////////
 
 
diff --git a/test/data/test-data.js b/test/data/test-data.js
index aee1031..6076925 100644
--- a/test/data/test-data.js
+++ b/test/data/test-data.js
@@ -101,6 +101,16 @@ const fitFileDevDataWithoutFieldDescription = [
     0x5C, 0xF2, 0x6D, 0x00, 0x36, 0xEE, 0x80, 0x78, 0x3B
 ];
 
+const fitFileShortMultibyteDevData = [
+    0x0E, 0x20, 0xB9, 0x52, 0x3F, 0x00, 0x00, 0x00, 0x2E, 0x46, 0x49, 0x54,
+    0xED, 0x8A, 0x40, 0x00, 0x01, 0x00, 0xCF, 0x01, 0x03, 0x01, 0x02, 0x00,
+    0x00, 0x40, 0x00, 0x01, 0x00, 0xCE, 0x05, 0x00, 0x01, 0x02, 0x01, 0x01,
+    0x02, 0x02, 0x01, 0x02, 0x08, 0x07, 0x07, 0x0E, 0x02, 0x84, 0x00, 0x00,
+    0x00, 0x84, 0x70, 0x6F, 0x69, 0x6E, 0x74, 0x73, 0x00, 0x00, 0x12, 0x60,
+    0x00, 0x01, 0x00, 0x12, 0x01, 0xFE, 0x02, 0x84, 0x01, 0x00, 0x02, 0x00,
+    0x00, 0x00, 0x00, 0x04, 0xD2, 0x97, 0x59
+];
+
 const fitFileMonitoring = [
     0x0E, 0x10, 0x28, 0x23, 0x37, 0x00, 0x00, 0x00, 0x2E, 0x46, 0x49, 0x54,
     0x2C, 0xC6, 0x41, 0x00, 0x01, 0x00, 0x37, 0x03, 0xFD, 0x04, 0x86, 0x18,
@@ -677,6 +687,7 @@ export default {
     fitFileChained,
     fitFileChainedWeirdVivoki,
     fitFileDevDataWithoutFieldDescription,
+    fitFileShortMultibyteDevData,
     fitFileMonitoring,
     fitFileAccumulatedComponents,
     fitFileCompressedSpeedAndDistanceWithInitialDistance,
diff --git a/test/decoder.test.js b/test/decoder.test.js
index 864cf33..2fdddea 100644
--- a/test/decoder.test.js
+++ b/test/decoder.test.js
@@ -161,6 +161,20 @@ describe("Decoder Tests", () => {
         });
     });
 
+    describe("Profile Version Tests", () => {
+        test("Profile version should be parsed and returned", () => {
+            const buf = fs.readFileSync("test/data/WithGearChangeData.fit");
+            const stream = Stream.fromBuffer(buf);
+            const decode = new Decoder(stream);
+            const { profileVersion, errors } = decode.read();
+            expect(errors.length).toBe(0);
+            expect(profileVersion).toEqual({
+                major: 21,
+                minor: 173
+            });
+        });
+    });
+
     describe("Skip Header Flag Tests", () => {
         test("File with invalid header should not fail when skipHeader: true", () => {
             const stream = Stream.fromByteArray(Data.fitFileShortInvalidHeader);
@@ -376,6 +390,16 @@ describe("Decoder Tests", () => {
             expect(errors.length).toBe(0);
             expect(messages.activityMesgs.length).toBe(1);
         });
+
+        test("When Developer Data is a multibyte base type, it should be decoded correctly", () => {
+            const stream = Stream.fromByteArray(Data.fitFileShortMultibyteDevData);
+            const decode = new Decoder(stream);
+            const { messages, errors } = decode.read();
+            expect(errors.length).toBe(0);
+            expect(messages.sessionMesgs.length).toBe(1);
+
+            expect(messages.sessionMesgs[0].developerFields[0]).toBe(1234);
+        });
     });
 
     describe("Component Expansion Tests", () => {
diff --git a/test/encoder.test.js b/test/encoder.test.js
index ba860bf..7789696 100644
--- a/test/encoder.test.js
+++ b/test/encoder.test.js
@@ -171,6 +171,55 @@ describe("Encoder Tests", () => {
             encoder.close();
         });
     });
+
+    test("Encoder writes base types with endianness bit", () => {
+        const fileIdMesg = {
+            product: 0x1234,
+        }
+
+        const encoder = new Encoder();
+        encoder.onMesg(Profile.MesgNum.FILE_ID, fileIdMesg);
+        const uint8Array = encoder.close();
+
+        // Base type UINT16 with endianness is 0x84
+        expect(uint8Array[22]).toBe(0x84);
+    })
+
+    test("Encoder writes developer data field base types with endianness bit", () => {
+        const developerDataIdMesg = {
+            developerDataIndex: 0,
+        };
+
+        const fieldDescriptionMesg = {
+            developerDataIndex: 0,
+            fieldDefinitionNumber: 1,
+            fitBaseTypeId: 0x84,
+        };
+
+        const fieldDescriptions = {
+            0: {
+                developerDataIdMesg,
+                fieldDescriptionMesg,
+            },
+        };
+
+        const sessionMesg = {
+            messageIndex: 2,
+            developerFields: {
+                0: 0x1234
+            },
+        };
+
+        const encoder = new Encoder({ fieldDescriptions });
+
+        encoder.onMesg(Profile.MesgNum.DEVELOPER_DATA_ID, developerDataIdMesg);
+        encoder.onMesg(Profile.MesgNum.FIELD_DESCRIPTION, fieldDescriptionMesg);
+        encoder.onMesg(Profile.MesgNum.SESSION, sessionMesg);
+        const uint8Array = encoder.close();
+
+        // Dev data FIT Base type UINT16 with endianness is 0x84
+        expect(uint8Array[43]).toBe(0x84);
+    });
 });
 
 describe("Encoder-Decoder Integration Tests", () => {
@@ -306,5 +355,49 @@ describe("Encoder-Decoder Integration Tests", () => {
             throw error;
         }
     });
+
+    test("Encoder should correctly encode and decode fields and developer fields with mulitbyte base types", () => {
+        const developerDataIdMesg = {
+            developerDataIndex: 0,
+        };
+
+        const fieldDescriptionMesg = {
+            developerDataIndex: 0,
+            fieldDefinitionNumber: 1,
+            fitBaseTypeId: 0x84,
+        };
+
+        const fileIdMesg = {
+            product: 0x5555,
+            developerFields: {
+                0: 0x1234
+            },
+        };
+
+        const fieldDescriptions = {
+            0: {
+                developerDataIdMesg,
+                fieldDescriptionMesg,
+            },
+        };
+
+        const encoder = new Encoder({ fieldDescriptions });
+
+        encoder.onMesg(Profile.MesgNum.DEVELOPER_DATA_ID, developerDataIdMesg);
+        encoder.onMesg(Profile.MesgNum.FIELD_DESCRIPTION, fieldDescriptionMesg);
+        encoder.onMesg(Profile.MesgNum.FILE_ID, fileIdMesg);
+
+        const stream = Stream.fromByteArray(encoder.close());
+        const decoder = new Decoder(stream);
+
+        const { messages, errors, } = decoder.read(DECODER_OPTIONS);
+
+        expect(errors.length).toBe(0);
+        expect(messages.fileIdMesgs.length).toBe(1);
+
+        const decodedFileIdMesg = messages.fileIdMesgs[0];
+        expect(decodedFileIdMesg.product).toBe(fileIdMesg.product);
+        expect(decodedFileIdMesg.developerFields[0]).toBe(fileIdMesg.developerFields[0]);
+    });
 });