diff --git a/include/lib/cpus/aarch64/cortex_x2.h b/include/lib/cpus/aarch64/cortex_x2.h
index e1695cd..e3d0fa9 100644
--- a/include/lib/cpus/aarch64/cortex_x2.h
+++ b/include/lib/cpus/aarch64/cortex_x2.h
@@ -34,6 +34,7 @@
  * CPU Auxiliary Control Register 5 definitions
  ******************************************************************************/
 #define CORTEX_X2_CPUACTLR5_EL1					S3_0_C15_C8_0
+#define CORTEX_X2_CPUACTLR5_EL1_BIT_17				(ULL(1) << 17)
 
 /*******************************************************************************
  * CPU Implementation Specific Selected Instruction registers