diff --git a/configs/sam3u-ek/ostest/defconfig b/configs/sam3u-ek/ostest/defconfig
index fe4a46deb0..ff18be8f10 100755
--- a/configs/sam3u-ek/ostest/defconfig
+++ b/configs/sam3u-ek/ostest/defconfig
@@ -100,6 +100,11 @@ CONFIG_SAM3U_BUILDROOT=y
 #
 #  Individual subsystems can be enabled:
 #
+CONFIG_SAM3U_USART0=y
+CONFIG_SAM3U_USART1=y
+CONFIG_SAM3U_USART2=y
+CONFIG_SAM3U_USART3=y
+
 #
 # SAM3U specific serial device driver settings
 #
@@ -109,52 +114,45 @@ CONFIG_SAM3U_BUILDROOT=y
 #   This specific the size of the receive buffer
 # CONFIG_USARTn_TXBUFSIZE - Characters are buffered before
 #   being sent.  This specific the size of the transmit buffer
-# CONFIG_USARTn_BAUD - The configure BAUD of the UART.  Must be
+# CONFIG_USARTn_BAUD - The configure BAUD of the USART.  Must be
 # CONFIG_USARTn_BITS - The number of bits.  Must be either 7 or 8.
 # CONFIG_USARTn_PARTIY - 0=no parity, 1=odd parity, 2=even parity
 # CONFIG_USARTn_2STOP - Two stop bits
 #
-CONFIG_USART1_SERIAL_CONSOLE=y
+CONFIG_USART0_SERIAL_CONSOLE=Y
+CONFIG_USART1_SERIAL_CONSOLE=n
 CONFIG_USART2_SERIAL_CONSOLE=n
 CONFIG_USART3_SERIAL_CONSOLE=n
-CONFIG_USART4_SERIAL_CONSOLE=n
-CONFIG_USART5_SERIAL_CONSOLE=n
 
+CONFIG_USART0_TXBUFSIZE=256
 CONFIG_USART1_TXBUFSIZE=256
 CONFIG_USART2_TXBUFSIZE=256
 CONFIG_USART3_TXBUFSIZE=256
-CONFIG_USART4_TXBUFSIZE=256
-CONFIG_USART5_TXBUFSIZE=256
 
+CONFIG_USART0_RXBUFSIZE=256
 CONFIG_USART1_RXBUFSIZE=256
 CONFIG_USART2_RXBUFSIZE=256
 CONFIG_USART3_RXBUFSIZE=256
-CONFIG_USART4_RXBUFSIZE=256
-CONFIG_USART5_RXBUFSIZE=256
 
+CONFIG_USART0_BAUD=115200
 CONFIG_USART1_BAUD=115200
 CONFIG_USART2_BAUD=115200
 CONFIG_USART3_BAUD=115200
-CONFIG_USART4_BAUD=115200
-CONFIG_USART5_BAUD=115200
 
+CONFIG_USART0_BITS=8
 CONFIG_USART1_BITS=8
 CONFIG_USART2_BITS=8
 CONFIG_USART3_BITS=8
-CONFIG_USART4_BITS=8
-CONFIG_USART5_BITS=8
 
+CONFIG_USART0_PARITY=0
 CONFIG_USART1_PARITY=0
 CONFIG_USART2_PARITY=0
 CONFIG_USART3_PARITY=0
-CONFIG_USART4_PARITY=0
-CONFIG_USART5_PARITY=0
 
+CONFIG_USART0_2STOP=0
 CONFIG_USART1_2STOP=0
 CONFIG_USART2_2STOP=0
 CONFIG_USART3_2STOP=0
-CONFIG_USART4_2STOP=0
-CONFIG_USART5_2STOP=0
 
 #
 # General build options