diff --git a/include/bl31/interrupt_mgmt.h b/include/bl31/interrupt_mgmt.h
index 905dcd6..13c46e3 100644
--- a/include/bl31/interrupt_mgmt.h
+++ b/include/bl31/interrupt_mgmt.h
@@ -101,9 +101,9 @@
  ******************************************************************************/
 #define INTR_SRC_SS_FLAG_SHIFT		U(0)		/* BIT[0] */
 #define INTR_SRC_SS_FLAG_MASK		U(1)
-#define set_interrupt_src_ss(flag, val)	(flag |= val << INTR_SRC_SS_FLAG_SHIFT)
-#define clr_interrupt_src_ss(flag)	(flag &= ~(U(1) << INTR_SRC_SS_FLAG_SHIFT))
-#define get_interrupt_src_ss(flag)	((flag >> INTR_SRC_SS_FLAG_SHIFT) & \
+#define set_interrupt_src_ss(flag, val)	((flag) |= (val) << INTR_SRC_SS_FLAG_SHIFT)
+#define clr_interrupt_src_ss(flag)	((flag) &= ~(U(1) << INTR_SRC_SS_FLAG_SHIFT))
+#define get_interrupt_src_ss(flag)	(((flag) >> INTR_SRC_SS_FLAG_SHIFT) & \
 					 INTR_SRC_SS_FLAG_MASK)
 
 #ifndef __ASSEMBLY__