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
@@ -308,14 +308,19 @@
       const creatorID = this.props.viewerID;
       invariant(creatorID, 'need viewer ID in order to send a message');
       const media = uploads.map(
-        ({ localID, serverID, uri, mediaType, dimensions, encryptionKey }) => {
+        ({
+          localID,
+          serverID,
+          uri,
+          mediaType,
+          dimensions,
+          encryptionKey,
+          thumbHash,
+        }) => {
           // We can get into this state where dimensions are null if the user is
           // uploading a file type that the browser can't render. In that case
           // we fake the dimensions here while we wait for the server to tell us
-          // the true dimensions. We actually don't use the dimensions on the
-          // web side currently, but if we ever change that (for instance if we
-          // want to render a properly sized loading overlay like we do on
-          // native), 0,0 is probably a good default.
+          // the true dimensions.
           const shimmedDimensions = dimensions ?? { height: 0, width: 0 };
           invariant(
             mediaType === 'photo' || mediaType === 'encrypted_photo',
@@ -330,7 +335,7 @@
               uri,
               type: 'photo',
               dimensions: shimmedDimensions,
-              thumbHash: null,
+              thumbHash,
             };
           }
           invariant(
@@ -343,7 +348,7 @@
             type: 'encrypted_photo',
             encryptionKey,
             dimensions: shimmedDimensions,
-            thumbHash: null,
+            thumbHash,
           };
         },
       );