diff --git a/ts/types/MIME.ts b/ts/types/MIME.ts
index 85be83fa3..6ad989498 100644
--- a/ts/types/MIME.ts
+++ b/ts/types/MIME.ts
@@ -26,8 +26,11 @@ export const VIDEO_MP4 = stringToMIMEType('video/mp4');
 export const VIDEO_QUICKTIME = stringToMIMEType('video/quicktime');
 export const LONG_MESSAGE = stringToMIMEType('text/x-signal-plain');
 
-export const isHeic = (value: string): boolean =>
-  value === 'image/heic' || value === 'image/heif';
+export const isHeic = (value: string, fileName: string): boolean =>
+  value === 'image/heic' ||
+  value === 'image/heif' ||
+  fileName.endsWith('.heic') ||
+  fileName.endsWith('.heif');
 export const isGif = (value: string): value is MIMEType =>
   value === 'image/gif';
 export const isJPEG = (value: string): value is MIMEType =>
diff --git a/ts/util/handleImageAttachment.ts b/ts/util/handleImageAttachment.ts
index 99954e920..5b15a207a 100644
--- a/ts/util/handleImageAttachment.ts
+++ b/ts/util/handleImageAttachment.ts
@@ -18,7 +18,7 @@ export async function handleImageAttachment(
 ): Promise<InMemoryAttachmentDraftType> {
   let processedFile: File | Blob = file;
 
-  if (isHeic(file.type)) {
+  if (isHeic(file.type, file.name)) {
     const uuid = genUuid();
     const bytes = new Uint8Array(await file.arrayBuffer());
 
@@ -41,7 +41,9 @@ export async function handleImageAttachment(
     file: resizedBlob,
     fileName,
   } = await autoScale({
-    contentType: isHeic(file.type) ? IMAGE_JPEG : stringToMIMEType(file.type),
+    contentType: isHeic(file.type, file.name)
+      ? IMAGE_JPEG
+      : stringToMIMEType(file.type),
     fileName: file.name,
     file: processedFile,
   });
diff --git a/ts/util/processAttachment.ts b/ts/util/processAttachment.ts
index d818dfb88..b85a63b16 100644
--- a/ts/util/processAttachment.ts
+++ b/ts/util/processAttachment.ts
@@ -82,7 +82,7 @@ export async function processAttachment(
 
   let attachment: InMemoryAttachmentDraftType;
   try {
-    if (isImageTypeSupported(fileType) || isHeic(fileType)) {
+    if (isImageTypeSupported(fileType) || isHeic(fileType, file.name)) {
       attachment = await handleImageAttachment(file);
     } else if (isVideoTypeSupported(fileType)) {
       attachment = await handleVideoAttachment(file);