diff --git a/sphaira/source/usb/usbds.cpp b/sphaira/source/usb/usbds.cpp
index 5427ec3..13aff7e 100644
--- a/sphaira/source/usb/usbds.cpp
+++ b/sphaira/source/usb/usbds.cpp
@@ -293,11 +293,13 @@ Result UsbDs::WaitTransferCompletion(UsbSessionEndpoint ep, u64 timeout) {
 }
 
 Result UsbDs::TransferAsync(UsbSessionEndpoint ep, void *buffer, u32 remaining, u32 size, u32 *out_urb_id) {
-    if (remaining == size && !(size % (u32)m_max_packet_size)) {
-        log_write("[USBDS] SetZlt(true)\n");
-        R_TRY(usbDsEndpoint_SetZlt(m_endpoints[ep], true));
-    } else {
-        R_TRY(usbDsEndpoint_SetZlt(m_endpoints[ep], false));
+    if (ep == UsbSessionEndpoint_In) {
+        if (remaining == size && !(size % (u32)m_max_packet_size)) {
+            log_write("[USBDS] SetZlt(true)\n");
+            R_TRY(usbDsEndpoint_SetZlt(m_endpoints[ep], true));
+        } else {
+            R_TRY(usbDsEndpoint_SetZlt(m_endpoints[ep], false));
+        }
     }
 
     return usbDsEndpoint_PostBufferAsync(m_endpoints[ep], buffer, size, out_urb_id);