diff --git a/lib/reducers/message-reducer.js b/lib/reducers/message-reducer.js
--- a/lib/reducers/message-reducer.js
+++ b/lib/reducers/message-reducer.js
@@ -1437,12 +1437,20 @@
           singleMedia.type === 'encrypted_photo' &&
           mediaUpdate.type === 'encrypted_photo'
         ) {
+          // TODO: Remove this $FlowFixMe after updating Flow to 0.202
+          // There's no way in Flow to refine both of these types appropriately
+          // so they can be spread together.
+          // $FlowFixMe
           media.push({ ...singleMedia, ...mediaUpdate });
           replaced = true;
         } else if (
           singleMedia.type === 'encrypted_video' &&
           mediaUpdate.type === 'encrypted_video'
         ) {
+          // TODO: Remove this $FlowFixMe after updating Flow to 0.202
+          // There's no way in Flow to refine both of these types appropriately
+          // so they can be spread together.
+          // $FlowFixMe
           media.push({ ...singleMedia, ...mediaUpdate });
           replaced = true;
         } else if (
@@ -1451,16 +1459,22 @@
         ) {
           // extract fields that are absent in encrypted_photo type
           const { uri, localMediaSelection, ...original } = singleMedia;
-          const { holder, encryptionKey, ...update } = mediaUpdate;
+          const {
+            holder: newHolder,
+            blobURI: newBlobURI,
+            encryptionKey,
+            ...update
+          } = mediaUpdate;
+          const blobURI = newBlobURI ?? newHolder;
           invariant(
-            holder && encryptionKey,
+            blobURI && encryptionKey,
             'holder and encryptionKey are required for encrypted_photo message',
           );
           media.push({
             ...original,
             ...update,
             type: 'encrypted_photo',
-            holder,
+            blobURI,
             encryptionKey,
           });
           replaced = true;
@@ -1471,18 +1485,22 @@
           const { uri, thumbnailURI, localMediaSelection, ...original } =
             singleMedia;
           const {
-            holder,
+            holder: newHolder,
+            blobURI: newBlobURI,
             encryptionKey,
-            thumbnailHolder,
+            thumbnailHolder: newThumbnailHolder,
+            thumbnailBlobURI: newThumbnailBlobURI,
             thumbnailEncryptionKey,
             ...update
           } = mediaUpdate;
+          const blobURI = newBlobURI ?? newHolder;
           invariant(
-            holder && encryptionKey,
+            blobURI && encryptionKey,
             'holder and encryptionKey are required for encrypted_video message',
           );
+          const thumbnailBlobURI = newThumbnailBlobURI ?? newThumbnailHolder;
           invariant(
-            thumbnailHolder && thumbnailEncryptionKey,
+            thumbnailBlobURI && thumbnailEncryptionKey,
             'thumbnailHolder and thumbnailEncryptionKey are required for ' +
               'encrypted_video message',
           );
@@ -1490,9 +1508,9 @@
             ...original,
             ...update,
             type: 'encrypted_video',
-            holder,
+            blobURI,
             encryptionKey,
-            thumbnailHolder,
+            thumbnailBlobURI,
             thumbnailEncryptionKey,
           });
           replaced = true;
@@ -1504,9 +1522,27 @@
           } else if (singleMedia.type === 'video') {
             media.push({ ...singleMedia, id: newID });
           } else if (singleMedia.type === 'encrypted_photo') {
-            media.push({ ...singleMedia, id: newID });
+            // TODO: Try removing this branching after Flow 0.202 update
+            if (singleMedia.blobURI) {
+              media.push({ ...singleMedia, id: newID });
+            } else {
+              invariant(
+                singleMedia.holder,
+                'Encrypted media must have holder or blobURI',
+              );
+              media.push({ ...singleMedia, id: newID });
+            }
           } else if (singleMedia.type === 'encrypted_video') {
-            media.push({ ...singleMedia, id: newID });
+            // TODO: Try removing this branching after Flow 0.202 update
+            if (singleMedia.blobURI) {
+              media.push({ ...singleMedia, id: newID });
+            } else {
+              invariant(
+                singleMedia.holder,
+                'Encrypted media must have holder or blobURI',
+              );
+              media.push({ ...singleMedia, id: newID });
+            }
           }
           replaced = true;
         }
diff --git a/lib/types/media-types.js b/lib/types/media-types.js
--- a/lib/types/media-types.js
+++ b/lib/types/media-types.js
@@ -77,7 +77,7 @@
 export type UpdateMultimediaMessageMediaPayload = {
   +messageID: string,
   +currentMediaID: string,
-  +mediaUpdate: Shape<Media>,
+  +mediaUpdate: MediaShape,
 };
 
 export type UploadDeletionRequest = {
@@ -763,6 +763,11 @@
 ]);
 
 export type Media = Image | Video | EncryptedImage | EncryptedVideo;
+export type MediaShape =
+  | Shape<Image>
+  | Shape<Video>
+  | Shape<EncryptedImage>
+  | Shape<EncryptedVideo>;
 
 export const mediaValidator: TUnion<Media> = t.union([
   imageValidator,
diff --git a/native/input/input-state-container.react.js b/native/input/input-state-container.react.js
--- a/native/input/input-state-container.react.js
+++ b/native/input/input-state-container.react.js
@@ -974,7 +974,7 @@
         processedMedia.mediaType === 'encrypted_video'
           ? {
               type: processedMedia.mediaType,
-              holder: uri,
+              blobURI: uri,
               encryptionKey,
             }
           : {
@@ -1008,7 +1008,7 @@
             mediaUpdate: {
               ...updateMediaPayload.mediaUpdate,
               thumbnailID,
-              thumbnailHolder: thumbnailURI,
+              thumbnailBlobURI: thumbnailURI,
               thumbnailEncryptionKey,
               thumbnailThumbHash,
             },
diff --git a/web/input/input-state-container.react.js b/web/input/input-state-container.react.js
--- a/web/input/input-state-container.react.js
+++ b/web/input/input-state-container.react.js
@@ -349,7 +349,7 @@
           );
           return {
             id: serverID ? serverID : localID,
-            holder: uri,
+            blobURI: uri,
             type: 'encrypted_photo',
             encryptionKey,
             dimensions: shimmedDimensions,
@@ -1017,7 +1017,7 @@
         mediaUpdate = {
           ...mediaUpdate,
           type: outputMediaType,
-          holder: uri,
+          blobURI: uri,
           encryptionKey,
         };
       }