diff --git a/sasjs-tests/vite.config.js b/sasjs-tests/vite.config.js
index 44484a7..5834b10 100644
--- a/sasjs-tests/vite.config.js
+++ b/sasjs-tests/vite.config.js
@@ -1,5 +1,12 @@
 import { defineConfig } from 'vite'
+import { nodePolyfills } from 'vite-plugin-node-polyfills'
+
 export default defineConfig({
+  plugins: [
+    nodePolyfills({
+      include: ['buffer']
+    })
+  ],
   build: {
     assetsInlineLimit: 0,
     assetsDir: ''
diff --git a/src/SASViyaApiClient.ts b/src/SASViyaApiClient.ts
index c89375b..473c773 100644
--- a/src/SASViyaApiClient.ts
+++ b/src/SASViyaApiClient.ts
@@ -481,11 +481,14 @@ export class SASViyaApiClient {
     if (!parentFolderUri && parentFolderPath) {
       parentFolderUri = await this.getFolderUri(parentFolderPath, accessToken)
     }
-
     const headers = {
       Accept: 'application/vnd.sas.file+json',
       'Content-Disposition': `filename="${fileName}";`
     }
+    const patchHeaders = {
+      Accept: 'application/json',
+      'If-Match': '*'
+    }
 
     const formData = new NodeFormData()
     formData.append('file', contentBuffer, fileName)
@@ -529,7 +532,8 @@ export class SASViyaApiClient {
           .forEach((e) => {
             e.extensions?.forEach((ext) => {
               this.fileExtensionMap.set(ext, {
-                typeDefName: e.name, // "name:" is the typeDefName value required for file creation.
+                // "name:" is the typeDefName value required for file creation.
+                typeDefName: e.name,
                 properties: e.properties
               })
             })
@@ -546,34 +550,38 @@ export class SASViyaApiClient {
       }
     }
 
-    return (
-      await this.requestClient
-        .post<File>(
-          `/files/files?parentFolderUri=${parentFolderUri}&typeDefName=${
-            typeDefName ?? 'file'
-          }#rawUpload`,
-          formData,
-          accessToken,
-          'multipart/form-data; boundary=' + (formData as any)._boundary,
-          headers
-        )
-        .then(async (res) => {
-          // If a patch was created...
-          if (filePatch) {
-            // Get the URI of the newly created file
-            const fileUri = res.result.links.filter(
-              (e) => e.method == 'PATCH' && e.rel == 'patch'
-            )[0].uri
-            // and apply the patch
-            return await this.requestClient.patch<File>(
-              `${fileUri}`,
-              filePatch,
-              accessToken
-            )
-          }
-          return res
-        })
-    ).result
+    const createFileResponse = await this.requestClient.post<File>(
+      `/files/files?parentFolderUri=${parentFolderUri}&typeDefName=${
+        typeDefName ?? 'file'
+      }#rawUpload`,
+      formData,
+      accessToken,
+      'multipart/form-data; boundary=' + (formData as any)._boundary,
+      headers
+    )
+
+    try {
+      // If a patch was created...
+      if (filePatch) {
+        // Get the URI of the newly created file
+        const fileUri = createFileResponse.result.links.filter(
+          (e) => e.method == 'PATCH' && e.rel == 'patch'
+        )[0].uri
+        // and apply the patch
+        return (
+          await this.requestClient.patch<File>(
+            `${fileUri}`,
+            filePatch,
+            accessToken,
+            'application/json',
+            patchHeaders
+          )
+        ).result
+      }
+      return createFileResponse.result
+    } catch (e: any) {
+      throw new Error(`Error patching file ${fileName}.\n${e.message}`)
+    }
   }
 
   /**
diff --git a/src/request/RequestClient.ts b/src/request/RequestClient.ts
index c0295ed..f8cb470 100644
--- a/src/request/RequestClient.ts
+++ b/src/request/RequestClient.ts
@@ -272,10 +272,15 @@ export class RequestClient implements HttpClient {
 
   public async patch<T>(
     url: string,
-    data: any = {},
-    accessToken?: string
+    data: any,
+    accessToken: string | undefined,
+    contentType = 'application/json',
+    overrideHeaders: { [key: string]: string | number } = {}
   ): Promise<{ result: T; etag: string }> {
-    const headers = this.getHeaders(accessToken, 'application/json')
+    const headers = {
+      ...this.getHeaders(accessToken, contentType),
+      ...overrideHeaders
+    }
 
     return this.httpClient
       .patch<T>(url, data, { headers, withXSRFToken: true })