diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst
index 2e3fe74..b053647 100644
--- a/docs/design/cpu-specific-build-macros.rst
+++ b/docs/design/cpu-specific-build-macros.rst
@@ -331,6 +331,10 @@
   Cortex-A78C CPU. This needs to be enabled for revisions r0p1, r0p2 and
   it is still open.
 
+- ``ERRATA_A78C_2242638`` : This applies errata 2242638 workaround to
+  Cortex-A78C CPU. This needs to be enabled for revisions r0p1, r0p2 and
+  it is still open.
+
 For Cortex-X1 CPU, the following errata build flags are defined:
 
 - ``ERRATA_X1_1821534`` : This applies errata 1821534 workaround to Cortex-X1
diff --git a/include/lib/cpus/aarch64/cortex_a78c.h b/include/lib/cpus/aarch64/cortex_a78c.h
index 39e2adf..54c95ad 100644
--- a/include/lib/cpus/aarch64/cortex_a78c.h
+++ b/include/lib/cpus/aarch64/cortex_a78c.h
@@ -26,4 +26,12 @@
 #define CORTEX_A78C_CPUPWRCTLR_EL1			S3_0_C15_C2_7
 #define CORTEX_A78C_CPUPWRCTLR_EL1_CORE_PWRDN_EN_BIT	U(1)
 
+/*******************************************************************************
+ * CPU Implementation Specific Selected Instruction registers
+ ******************************************************************************/
+#define CORTEX_A78C_IMP_CPUPSELR_EL3			S3_6_C15_C8_0
+#define CORTEX_A78C_IMP_CPUPCR_EL3			S3_6_C15_C8_1
+#define CORTEX_A78C_IMP_CPUPOR_EL3			S3_6_C15_C8_2
+#define CORTEX_A78C_IMP_CPUPMR_EL3			S3_6_C15_C8_3
+
 #endif /* CORTEX_A78C_H */
diff --git a/lib/cpus/aarch64/cortex_a78c.S b/lib/cpus/aarch64/cortex_a78c.S
index f57ecaf..fc002e9 100644
--- a/lib/cpus/aarch64/cortex_a78c.S
+++ b/lib/cpus/aarch64/cortex_a78c.S
@@ -58,6 +58,41 @@
 	b	cpu_rev_var_range
 endfunc check_errata_2132064
 
+/* --------------------------------------------------------------------
+ * Errata Workaround for A78C Erratum 2242638.
+ * This applies to revisions r0p1 and r0p2 of the Cortex A78C
+ * processor and is still open.
+ * x0: variant[4:7] and revision[0:3] of current cpu.
+ * Shall clobber: x0-x17
+ * --------------------------------------------------------------------
+ */
+func errata_a78c_2242638_wa
+	/* Compare x0 against revisions r0p1 - r0p2 */
+	mov	x17, x30
+	bl	check_errata_2242638
+	cbz	x0, 1f
+
+	ldr	x0, =0x5
+	msr	CORTEX_A78C_IMP_CPUPSELR_EL3, x0
+	ldr	x0, =0x10F600E000
+	msr	CORTEX_A78C_IMP_CPUPOR_EL3, x0
+	ldr	x0, =0x10FF80E000
+	msr	CORTEX_A78C_IMP_CPUPMR_EL3, x0
+	ldr	x0, =0x80000000003FF
+	msr	CORTEX_A78C_IMP_CPUPCR_EL3, x0
+
+	isb
+1:
+	ret	x17
+endfunc errata_a78c_2242638_wa
+
+func check_errata_2242638
+	/* Applies to revisions r0p1-r0p2. */
+	mov	x1, #CPU_REV(0, 1)
+	mov	x2, #CPU_REV(0, 2)
+	b	cpu_rev_var_range
+endfunc check_errata_2242638
+
 func check_errata_cve_2022_23960
 #if WORKAROUND_CVE_2022_23960
 	mov	x0, #ERRATA_APPLIES
@@ -81,6 +116,11 @@
 	bl	errata_a78c_2132064_wa
 #endif
 
+#if ERRATA_A78C_2242638
+	mov	x0, x18
+	bl	errata_a78c_2242638_wa
+#endif
+
 #if IMAGE_BL31 && WORKAROUND_CVE_2022_23960
 	/*
 	 * The Cortex-A78c generic vectors are overridden to apply errata
@@ -125,6 +165,7 @@
 	 * checking functions of each errata.
 	 */
 	report_errata ERRATA_A78C_2132064, cortex_a78c, 2132064
+	report_errata ERRATA_A78C_2242638, cortex_a78c, 2242638
 	report_errata WORKAROUND_CVE_2022_23960, cortex_a78c, cve_2022_23960
 
 	ldp	x8, x30, [sp], #16
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index 19e611c..2c08a27 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -365,6 +365,10 @@
 # to revisions r0p1 and r0p2 of the A78C cpu. It is still open.
 ERRATA_A78C_2132064	?=0
 
+# Flag to apply erratum 2242638 workaround during reset. This erratum applies
+# to revisions r0p1 and r0p2 of the A78C cpu. It is still open.
+ERRATA_A78C_2242638	?=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
@@ -923,6 +927,10 @@
 $(eval $(call assert_boolean,ERRATA_A78C_2132064))
 $(eval $(call add_define,ERRATA_A78C_2132064))
 
+# Process ERRATA_A78C_2242638 flag
+$(eval $(call assert_boolean,ERRATA_A78C_2242638))
+$(eval $(call add_define,ERRATA_A78C_2242638))
+
 # Process ERRATA_X1_1821534 flag
 $(eval $(call assert_boolean,ERRATA_X1_1821534))
 $(eval $(call add_define,ERRATA_X1_1821534))