diff --git a/cpu/cc253x/dev/uart0.c b/cpu/cc253x/dev/uart0.c
index a6a358a18..f5dc35640 100644
--- a/cpu/cc253x/dev/uart0.c
+++ b/cpu/cc253x/dev/uart0.c
@@ -39,7 +39,7 @@ uart0_init()
 #else
   PERCFG &= ~PERCFG_U0CFG; /* alternative port 1 = P0.5-2 */
 #ifdef UART0_RTSCTS
-  P0SEL |= 0x20 | 0x10;    /* peripheral select for TX and RX */
+  P0SEL |= 0x3C;    /* peripheral select for RTS and CTS, TX, RX */
 #else
   P0SEL |= 0x0C;    /* peripheral select for TX and RX */
   P0 &= ~0x20;    /* RTS down */