diff --git a/src/httpd.js.c b/src/httpd.js.c
index e7e2a20d..3c347ad6 100644
--- a/src/httpd.js.c
+++ b/src/httpd.js.c
@@ -1170,7 +1170,12 @@ static void _httpd_endpoint_view_work(tf_ssb_t* ssb, void* user_data)
 		}
 		else
 		{
-			tf_ssb_db_blob_get(ssb, blob_id, (uint8_t**)&view->data, &view->size);
+			if (!tf_ssb_db_blob_get(ssb, blob_id, (uint8_t**)&view->data, &view->size))
+			{
+				sqlite3* db = tf_ssb_acquire_db_writer(ssb);
+				tf_ssb_db_add_blob_wants(db, blob_id);
+				tf_ssb_release_db_writer(ssb, db);
+			}
 		}
 	}
 }
diff --git a/src/ssb.db.c b/src/ssb.db.c
index f2cbf48c..35aa533c 100644
--- a/src/ssb.db.c
+++ b/src/ssb.db.c
@@ -379,6 +379,15 @@ void tf_ssb_db_init(tf_ssb_t* ssb)
 		_tf_ssb_db_exec(db, "COMMIT TRANSACTION");
 		tf_printf("Done.\n");
 	}
+	if (!_tf_ssb_db_has_rows(db, "SELECT * FROM sqlite_schema WHERE type = 'index' AND name = 'blob_wants_cache_source_id_unique_index'"))
+	{
+		tf_printf("Creating blob_wants_cache UNIQUE constraint.\n");
+		_tf_ssb_db_exec(db, "BEGIN TRANSACTION");
+		_tf_ssb_db_exec(db, "DELETE FROM blob_wants_cache WHERE source IS NULL");
+		_tf_ssb_db_exec(db, "CREATE UNIQUE INDEX blob_wants_cache_source_id_unique_index ON blob_wants_cache (COALESCE(source, ''), id)");
+		_tf_ssb_db_exec(db, "COMMIT TRANSACTION");
+		tf_printf("Done.\n");
+	}
 	_tf_ssb_db_exec(db, "CREATE INDEX IF NOT EXISTS blob_wants_cache_id_idx ON blob_wants_cache (id)");
 	_tf_ssb_db_exec(db, "CREATE INDEX IF NOT EXISTS blob_wants_cache_timestamp_id_idx ON blob_wants_cache (timestamp, id)");
 
@@ -840,6 +849,31 @@ bool tf_ssb_db_blob_get(tf_ssb_t* ssb, const char* id, uint8_t** out_blob, size_
 	return result;
 }
 
+void tf_ssb_db_add_blob_wants(sqlite3* db, const char* id)
+{
+	sqlite3_stmt* statement;
+	if (sqlite3_prepare(db, "INSERT OR REPLACE INTO blob_wants_cache (id, timestamp) VALUES (?, unixepoch() * 1000) ON CONFLICT DO UPDATE SET timestamp = excluded.timestamp", -1,
+			&statement, NULL) == SQLITE_OK)
+	{
+		if (sqlite3_bind_text(statement, 1, id, -1, NULL) == SQLITE_OK)
+		{
+			if (sqlite3_step(statement) != SQLITE_DONE)
+			{
+				tf_printf("blob wants cache update failed: %s.\n", sqlite3_errmsg(db));
+			}
+			else
+			{
+				tf_printf("want: %s\n", id);
+			}
+		}
+		sqlite3_finalize(statement);
+	}
+	else
+	{
+		tf_printf("prepare failed: %s\n", sqlite3_errmsg(db));
+	}
+}
+
 typedef struct _blob_get_async_t
 {
 	tf_ssb_t* ssb;
diff --git a/src/ssb.db.h b/src/ssb.db.h
index 1b10b60e..c7f40030 100644
--- a/src/ssb.db.h
+++ b/src/ssb.db.h
@@ -599,4 +599,11 @@ typedef struct _tf_ssb_identity_info_t
 */
 tf_ssb_identity_info_t* tf_ssb_db_get_identity_info(tf_ssb_t* ssb, const char* user, const char* package_owner, const char* package_name);
 
+/**
+** Add or update a blob wants cache entry.
+** @param db The database.
+** @param id The wanted blob ID.
+*/
+void tf_ssb_db_add_blob_wants(sqlite3* db, const char* id);
+
 /** @} */