diff --git a/drivers/mfd/ucb1x00-core.c b/drivers/mfd/ucb1x00-core.c
index 252b74188ec20a7fbf55ee95410c9edfc41dc5ec..b281217334eb3c68d35c7695b8104dd327e6bcf6 100644
--- a/drivers/mfd/ucb1x00-core.c
+++ b/drivers/mfd/ucb1x00-core.c
@@ -27,6 +27,7 @@
 #include <linux/mutex.h>
 #include <linux/mfd/ucb1x00.h>
 #include <linux/gpio.h>
+#include <linux/semaphore.h>
 
 #include <mach/dma.h>
 #include <mach/hardware.h>
diff --git a/include/linux/mfd/ucb1x00.h b/include/linux/mfd/ucb1x00.h
index aa9c3789bed422f6fcb32ea72ace909481877ee3..4321f044d1e45e1ad5cdaf20eba1440427b1fb5e 100644
--- a/include/linux/mfd/ucb1x00.h
+++ b/include/linux/mfd/ucb1x00.h
@@ -12,6 +12,7 @@
 
 #include <linux/mfd/mcp.h>
 #include <linux/gpio.h>
+#include <linux/semaphore.h>
 
 #define UCB_IO_DATA	0x00
 #define UCB_IO_DIR	0x01