diff --git a/include/libopencm3/lpc13xx/gpio.h b/include/libopencm3/lpc13xx/gpio.h
index 7e44fe35..4a71625f 100644
--- a/include/libopencm3/lpc13xx/gpio.h
+++ b/include/libopencm3/lpc13xx/gpio.h
@@ -97,4 +97,10 @@
 #define GPIO2_IC			GPIO_IC(GPIO2)
 #define GPIO3_IC			GPIO_IC(GPIO3)
 
+BEGIN_DECLS
+
+void gpio_set(u32 gpioport, u16 gpios);
+
+END_DECLS
+
 #endif
diff --git a/lib/lpc43xx/ssp.c b/lib/lpc43xx/ssp.c
index e9cf5b09..d2b8ff1f 100644
--- a/lib/lpc43xx/ssp.c
+++ b/lib/lpc43xx/ssp.c
@@ -38,6 +38,9 @@
 #define CGU_AUTOBLOCK_CLOCK_BIT	11
 #define CGU_BASE_CLK_SEL_SHIFT	24   /* clock source selection (5 bits) */
 
+/* Local declarations. */
+void ssp_wait_until_not_busy(ssp_num_t ssp_num);
+
 /* Disable SSP */
 void ssp_disable(ssp_num_t ssp_num)
 {