diff --git a/src/SASViyaApiClient.ts b/src/SASViyaApiClient.ts
index 75fecb0..5b5d860 100644
--- a/src/SASViyaApiClient.ts
+++ b/src/SASViyaApiClient.ts
@@ -29,6 +29,7 @@ import { executeOnComputeApi } from './api/viya/executeOnComputeApi'
 import { getAccessTokenForViya } from './auth/getAccessTokenForViya'
 import { refreshTokensForViya } from './auth/refreshTokensForViya'
 import { FileContentUpdate } from './types/FileContentUpdate'
+import { FileResource } from './types/FileResource'
 
 interface JobExecutionResult {
   result?: { result: object }
@@ -324,7 +325,7 @@ export class SASViyaApiClient {
     fileName: string,
     accessToken?: string
   ) {
-    const { fileUri } = await this.getFileUri(
+    const fileUri = await this.getFileUri(
       folderPath,
       fileName,
       accessToken
@@ -354,7 +355,7 @@ export class SASViyaApiClient {
     content: string,
     accessToken?: string
   ) {
-    const { fileUri, etag } = await this.getFileUri(
+    const fileUri = await this.getFileUri(
       folderPath,
       fileName,
       accessToken
@@ -365,6 +366,18 @@ export class SASViyaApiClient {
       )
     })
 
+    // Fetch the file resource details to get the Etag and content type
+    const { result: originalFileResource, etag } =
+      await this.requestClient.get<FileResource>(
+        `${this.serverUrl}${fileUri}`,
+        accessToken
+      )
+
+    if (!originalFileResource || !etag)
+      throw new Error(
+        `File ${fileName} does not have an ETag, or request failed.`
+      )
+
     return await this.requestClient
       .put<FileContentUpdate>(
         `${this.serverUrl}${fileUri}/content`,
@@ -372,7 +385,7 @@ export class SASViyaApiClient {
         accessToken,
         {
           'If-Match': etag,
-          'Content-Type': 'text/plain'
+          'Content-Type': originalFileResource.contentType
         }
       )
       .then((res) => res.result)
@@ -1024,10 +1037,7 @@ export class SASViyaApiClient {
     folderPath: string,
     fileName: string,
     accessToken?: string
-  ): Promise<{
-    fileUri: string
-    etag: string
-  }> {
+  ): Promise<string> {
     const folderMembers = await this.listFolder(folderPath, accessToken, 1000, {
       returnDetails: true
     }).catch((err) => {
@@ -1044,21 +1054,7 @@ export class SASViyaApiClient {
     if (!fileUri)
       throw new Error(`File ${fileName} not found in folder: ${folderPath}`)
 
-    // Fetch the file details to get the resource ETag
-    const { etag } = await this.requestClient.get<File>(
-      `${this.serverUrl}${fileUri}`,
-      accessToken
-    )
-
-    if (!etag)
-      throw new Error(
-        `File ${fileName} does not have an ETag, or request failed.`
-      )
-
-    return {
-      fileUri,
-      etag: etag || ''
-    }
+    return fileUri
   }
 
   private async getRecycleBinUri(accessToken?: string) {
diff --git a/src/SASjs.ts b/src/SASjs.ts
index 71db4c8..33f05d1 100644
--- a/src/SASjs.ts
+++ b/src/SASjs.ts
@@ -411,6 +411,13 @@ export default class SASjs {
     )
   }
 
+  /**
+   * Fetches the file content for a file in the specified folder.
+   *
+   * @param folderPath - the full path to the folder containing the file. eg: /Public/folder1/folder2
+   * @param fileName - the name of the file in the `folderPath`
+   * @param accessToken - an access token for authorizing the request
+   */
   public async getFileContent(
     folderPath: string,
     fileName: string,
@@ -425,6 +432,14 @@ export default class SASjs {
     )
   }
 
+  /**
+   * Updates the file content for a file in the specified folder.
+   *
+   * @param folderPath - the full path to the folder containing the file. eg: /Public/folder1/folder2
+   * @param fileName - the name of the file in the `folderPath`
+   * @param content - the new content to be written to the file
+   * @param accessToken - an access token for authorizing the request
+   */
   public async updateFileContent(
     folderPath: string,
     fileName: string,
diff --git a/src/types/FileResource.ts b/src/types/FileResource.ts
new file mode 100644
index 0000000..5b1bd63
--- /dev/null
+++ b/src/types/FileResource.ts
@@ -0,0 +1,33 @@
+export interface FileResource {
+  creationTimeStamp: string
+  modifiedTimeStamp: string
+  createdBy: string
+  modifiedBy: string
+  id: string
+  properties: Properties
+  contentDisposition: string
+  contentType: string
+  encoding: string
+  links: Link[]
+  name: string
+  size: number
+  searchable: boolean
+  fileStatus: string
+  fileVersion: number
+  typeDefName: string
+  version: number
+  virusDetected: boolean
+  urlDetected: boolean
+  quarantine: boolean
+}
+
+export interface Link {
+  method: string
+  rel: string
+  href: string
+  uri: string
+  type?: string
+  responseType?: string
+}
+
+export interface Properties {}