diff --git a/adb/daemon/usb_ffs.cpp b/adb/daemon/usb_ffs.cpp
index 89348c2..07b4ba8 100644
--- a/adb/daemon/usb_ffs.cpp
+++ b/adb/daemon/usb_ffs.cpp
@@ -230,7 +230,7 @@
 
     if (out_control->get() < 0) {  // might have already done this before
         LOG(INFO) << "opening control endpoint " << USB_FFS_ADB_EP0;
-        control.reset(adb_open(USB_FFS_ADB_EP0, O_WRONLY));
+        control.reset(adb_open(USB_FFS_ADB_EP0, O_RDWR));
         if (control < 0) {
             PLOG(ERROR) << "cannot open control endpoint " << USB_FFS_ADB_EP0;
             return false;