diff --git a/include/lib/cpus/aarch64/cortex_a55.h b/include/lib/cpus/aarch64/cortex_a55.h
index 8b21e16..5db0f00 100644
--- a/include/lib/cpus/aarch64/cortex_a55.h
+++ b/include/lib/cpus/aarch64/cortex_a55.h
@@ -18,6 +18,13 @@
 #define CORTEX_A55_CPUPWRCTLR_EL1	S3_0_C15_C2_7
 #define CORTEX_A55_CPUECTLR_EL1		S3_0_C15_C1_4
 
+/*******************************************************************************
+ * CPU Auxiliary Control register specific definitions.
+ ******************************************************************************/
+#define CORTEX_A55_CPUACTLR_EL1				S3_0_C15_C1_0
+
+#define CORTEX_A55_CPUACTLR_EL1_DISABLE_DUAL_ISSUE	(ULL(1) << 31)
+
 /* Definitions of register field mask in CORTEX_A55_CPUPWRCTLR_EL1 */
 #define CORTEX_A55_CORE_PWRDN_EN_MASK	U(0x1)