diff --git a/lib/cpus/aarch64/cortex_x2.S b/lib/cpus/aarch64/cortex_x2.S
index 855d196..258288c 100644
--- a/lib/cpus/aarch64/cortex_x2.S
+++ b/lib/cpus/aarch64/cortex_x2.S
@@ -118,6 +118,14 @@
 
 check_erratum_ls cortex_x2, ERRATUM(2371105), CPU_REV(2, 0)
 
+workaround_reset_start cortex_x2, ERRATUM(2742423), ERRATA_X2_2742423
+	/* Set CPUACTLR5_EL1[56:55] to 2'b01 */
+	sysreg_bit_set CORTEX_X2_CPUACTLR5_EL1, BIT(55)
+	sysreg_bit_clear CORTEX_X2_CPUACTLR5_EL1, BIT(56)
+workaround_reset_end cortex_x2, ERRATUM(2742423)
+
+check_erratum_ls cortex_x2, ERRATUM(2742423), CPU_REV(2, 1)
+
 workaround_reset_start cortex_x2, ERRATUM(2768515), ERRATA_X2_2768515
 	/* dsb before isb of power down sequence */
 	dsb	sy
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index 8b167a8..434ee08 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -743,6 +743,10 @@
 # and is still open.
 CPU_FLAG_LIST += ERRATA_X2_2701952
 
+# Flag to apply erratum 2742423 workaround during reset. This erratum applies
+# to revisions r0p0, r1p0, r2p0 and r2p1 of the Cortex-X2 cpu and is still open.
+CPU_FLAG_LIST += ERRATA_X2_2742423
+
 # Flag to apply erratum 2768515 workaround during power down. This erratum
 # applies to revision r0p0, r1p0, r2p0 and r2p1 of the Cortex-X2 cpu and is
 # still open.