diff --git a/plat/rpi/rpi4/include/rpi_hw.h b/plat/rpi/rpi4/include/rpi_hw.h
index e46b0de..7185106 100644
--- a/plat/rpi/rpi4/include/rpi_hw.h
+++ b/plat/rpi/rpi4/include/rpi_hw.h
@@ -77,10 +77,15 @@
 #define RPI3_RNG_INT_MASK_DISABLE	U(0x1)
 
 /*
- * Serial port (called 'Mini UART' in the Broadcom documentation).
+ * Serial ports:
+ * 'Mini UART' in the BCM docucmentation is the 8250 compatible UART.
+ * There is also a PL011 UART, multiplexed to the same pins.
  */
 #define RPI4_IO_MINI_UART_OFFSET	ULL(0x00215040)
 #define RPI4_MINI_UART_BASE		(RPI_IO_BASE + RPI4_IO_MINI_UART_OFFSET)
+#define RPI4_IO_PL011_UART_OFFSET	ULL(0x00201000)
+#define RPI4_PL011_UART_BASE		(RPI_IO_BASE + RPI4_IO_PL011_UART_OFFSET)
+#define RPI4_PL011_UART_CLOCK		ULL(48000000)
 
 /*
  * GPIO controller