diff --git a/include/lib/aarch64/arch_helpers.h b/include/lib/aarch64/arch_helpers.h
index a013809..aa26203 100644
--- a/include/lib/aarch64/arch_helpers.h
+++ b/include/lib/aarch64/arch_helpers.h
@@ -196,6 +196,7 @@
  ******************************************************************************/
 DEFINE_SYSREG_READ_FUNC(midr_el1)
 DEFINE_SYSREG_READ_FUNC(mpidr_el1)
+DEFINE_SYSREG_READ_FUNC(id_aa64mmfr0_el1)
 
 DEFINE_SYSREG_RW_FUNCS(scr_el3)
 DEFINE_SYSREG_RW_FUNCS(hcr_el2)