diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index 2cbe13c..eb17dfd 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -357,6 +357,18 @@
 # to revisions r0p0 and r0p1 of the A78 AE cpu. It is still open.
 ERRATA_A78_AE_2395408	?=0
 
+# Flag to apply erratum 1821534 workaround during reset. This erratum applies
+# to revisions r0p0 - r1p0 of the X1 cpu and fixed in r1p1.
+ERRATA_X1_1821534	?=0
+
+# Flag to apply erratum 1688305 workaround during reset. This erratum applies
+# to revisions r0p0 - r1p0 of the X1 cpu and fixed in r1p1.
+ERRATA_X1_1688305	?=0
+
+# Flag to apply erratum 1827429 workaround during reset. This erratum applies
+# to revisions r0p0 - r1p0 of the X1 cpu and fixed in r1p1.
+ERRATA_X1_1827429	?=0
+
 # Flag to apply T32 CLREX workaround during reset. This erratum applies
 # only to r0p0 and r1p0 of the Neoverse N1 cpu.
 ERRATA_N1_1043202	?=0
@@ -878,6 +890,18 @@
 $(eval $(call assert_boolean,ERRATA_A78_AE_2395408))
 $(eval $(call add_define,ERRATA_A78_AE_2395408))
 
+# Process ERRATA_X1_1821534 flag
+$(eval $(call assert_boolean,ERRATA_X1_1821534))
+$(eval $(call add_define,ERRATA_X1_1821534))
+
+# Process ERRATA_X1_1688305 flag
+$(eval $(call assert_boolean,ERRATA_X1_1688305))
+$(eval $(call add_define,ERRATA_X1_1688305))
+
+# Process ERRATA_X1_1827429 flag
+$(eval $(call assert_boolean,ERRATA_X1_1827429))
+$(eval $(call add_define,ERRATA_X1_1827429))
+
 # Process ERRATA_N1_1043202 flag
 $(eval $(call assert_boolean,ERRATA_N1_1043202))
 $(eval $(call add_define,ERRATA_N1_1043202))