diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index e3b478d41..faf727bd4 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -41,6 +41,12 @@ Building on Windows is a pain, but is possible see our CI/Windows build machine
 1.  Install build tools `apt install build-essential cmake` (this installs make, g++, gcc)
 2.  Depending on your distro, you might need to install `hunspell` and `hunspell-<lan>` (e.g. `hunspell-en-au`)
 
+In Ubuntu, you may also need to install
+```
+sudo apt install cmake
+npm install cmake-js
+```
+
 ### All platforms
 
 Now, run these commands in your preferred terminal in a good directory for development:
diff --git a/ts/components/conversation/media-gallery/DocumentListItem.tsx b/ts/components/conversation/media-gallery/DocumentListItem.tsx
index a6f122fe5..73ffd54aa 100644
--- a/ts/components/conversation/media-gallery/DocumentListItem.tsx
+++ b/ts/components/conversation/media-gallery/DocumentListItem.tsx
@@ -35,6 +35,7 @@ export const DocumentListItem = (props: Props) => {
       messageTimestamp: props.mediaItem.messageTimestamp,
       attachment: props.mediaItem.attachment,
       conversationId: selectedConversationKey,
+      index: 0,
     });
   }, [
     selectedConversationKey,
diff --git a/ts/components/conversation/message/message-content/MessageAttachment.tsx b/ts/components/conversation/message/message-content/MessageAttachment.tsx
index 18f98c894..a8eb590a7 100644
--- a/ts/components/conversation/message/message-content/MessageAttachment.tsx
+++ b/ts/components/conversation/message/message-content/MessageAttachment.tsx
@@ -98,6 +98,7 @@ export const MessageAttachment = (props: Props) => {
           messageTimestamp,
           messageSender: attachmentProps?.sender,
           conversationId: attachmentProps?.convoId,
+          index: 0,
         });
       }
     },
diff --git a/ts/components/conversation/message/message-content/MessageContextMenu.tsx b/ts/components/conversation/message/message-content/MessageContextMenu.tsx
index d5c47625a..6832dc24a 100644
--- a/ts/components/conversation/message/message-content/MessageContextMenu.tsx
+++ b/ts/components/conversation/message/message-content/MessageContextMenu.tsx
@@ -299,6 +299,7 @@ export const MessageContextMenu = (props: Props) => {
       messageTimestamp,
       messageSender: sender,
       conversationId: convoId,
+      index: targetAttachmentIndex,
     });
   };
 
diff --git a/ts/types/Attachment.ts b/ts/types/Attachment.ts
index 5c2559d9a..c9daca7db 100644
--- a/ts/types/Attachment.ts
+++ b/ts/types/Attachment.ts
@@ -301,7 +301,7 @@ export const save = ({
 }: {
   attachment: AttachmentType;
   document: Document;
-  index?: number;
+  index: number;
   getAbsolutePath: (relativePath: string) => string;
   timestamp?: number;
 }): void => {
diff --git a/ts/util/attachmentsUtil.ts b/ts/util/attachmentsUtil.ts
index e0dc727ec..ffe0c2a1b 100644
--- a/ts/util/attachmentsUtil.ts
+++ b/ts/util/attachmentsUtil.ts
@@ -387,11 +387,13 @@ export const saveAttachmentToDisk = async ({
   messageTimestamp,
   messageSender,
   conversationId,
+  index,
 }: {
   attachment: AttachmentType;
   messageTimestamp: number;
   messageSender: string;
   conversationId: string;
+  index: number;
 }) => {
   const decryptedUrl = await getDecryptedMediaUrl(attachment.url, attachment.contentType, false);
   save({
@@ -399,6 +401,7 @@ export const saveAttachmentToDisk = async ({
     document,
     getAbsolutePath: getAbsoluteAttachmentPath,
     timestamp: messageTimestamp,
+    index,
   });
   await sendDataExtractionNotification(conversationId, messageSender, messageTimestamp);
 };