diff --git a/thread/docs/build-an-android-border-router.md b/thread/docs/build-an-android-border-router.md
index 63d89f7..f90a23b 100644
--- a/thread/docs/build-an-android-border-router.md
+++ b/thread/docs/build-an-android-border-router.md
@@ -169,7 +169,7 @@
     user thread_network
 ```
 
-For real RCP devices, it supports both SPI and UART interface and you can
+For real RCP devices, it supports both SPI and UART interfaces and you can
 specify the device with the schema `spinel+spi://`, `spinel+hdlc+uart://` and
 `spinel+socket://` respectively.