diff --git a/headers/os/kernel/OS.h b/headers/os/kernel/OS.h
index 7c4b41ebad..b738d747b9 100644
--- a/headers/os/kernel/OS.h
+++ b/headers/os/kernel/OS.h
@@ -147,13 +147,21 @@ typedef struct sem_info {
 
 /* semaphore flags */
 enum {
-	B_CAN_INTERRUPT		= 1,	/* acquisition of the semaphore can be interrupted (system use only) */
-	B_CHECK_PERMISSION	= 4,	/* ownership will be checked (system use only) */
+	B_CAN_INTERRUPT				= 0x01,	// acquisition of the semaphore can be
+										// interrupted (system use only)
+	B_CHECK_PERMISSION			= 0x04,	// ownership will be checked (system use
+										// only)
+	B_KILL_CAN_INTERRUPT		= 0x20,	// acquisition of the semaphore can be
+										// interrupted by SIGKILL[THR], even
+										// if not B_CAN_INTERRUPT (system use
+										// only)
 
 	/* release_sem_etc() only flags */
-	B_DO_NOT_RESCHEDULE	= 2,	/* thread is not rescheduled */
-	B_RELEASE_ALL		= 8,	/* all waiting threads will be woken up, count will be zeroed */
-	B_RELEASE_IF_WAITING_ONLY = 16,	/* release count only if there are any threads waiting */
+	B_DO_NOT_RESCHEDULE			= 0x02,	// thread is not rescheduled
+	B_RELEASE_ALL				= 0x08,	// all waiting threads will be woken up,
+										// count will be zeroed
+	B_RELEASE_IF_WAITING_ONLY	= 0x10,	// release count only if there are any
+										// threads waiting
 };
 
 extern sem_id	create_sem(int32 count, const char *name);