diff --git a/include/libcper/sections/cper-section-arm.h b/include/libcper/sections/cper-section-arm.h
index be65731..173d0bc 100644
--- a/include/libcper/sections/cper-section-arm.h
+++ b/include/libcper/sections/cper-section-arm.h
@@ -8,6 +8,8 @@
 #include <json.h>
 #include <libcper/Cper.h>
 
+#define ARM_SOCK_MASK 0xFF00000000
+
 #define ARM_ERROR_VALID_BITFIELD_NAMES                                         \
 	(const char *[])                                                       \
 	{                                                                      \
diff --git a/sections/cper-section-arm.c b/sections/cper-section-arm.c
index 119b30a..b07c829 100644
--- a/sections/cper-section-arm.c
+++ b/sections/cper-section-arm.c
@@ -73,8 +73,15 @@
 	json_object_object_add(section_ir, "errorAffinity", error_affinity);
 
 	//Processor ID (MPIDR_EL1) and chip ID (MIDR_EL1).
+	uint64_t sock;
+	uint64_t mpidr_eli1 = record->MPIDR_EL1;
 	json_object_object_add(section_ir, "mpidrEl1",
-			       json_object_new_uint64(record->MPIDR_EL1));
+			       json_object_new_uint64(mpidr_eli1));
+	//Arm Processor socket info
+	sock = (mpidr_eli1 & ARM_SOCK_MASK) >> 32;
+	json_object_object_add(section_ir, "affinity3",
+			       json_object_new_uint64(sock));
+
 	json_object_object_add(section_ir, "midrEl1",
 			       json_object_new_uint64(record->MIDR_EL1));
 
diff --git a/specification/json/sections/cper-arm-processor.json b/specification/json/sections/cper-arm-processor.json
index 6efb2ae..ec70748 100644
--- a/specification/json/sections/cper-arm-processor.json
+++ b/specification/json/sections/cper-arm-processor.json
@@ -8,6 +8,7 @@
         "sectionLength",
         "errorAffinity",
         "mpidrEl1",
+        "affinity3",
         "midrEl1",
         "running",
         "errorInfo",
@@ -62,6 +63,9 @@
         "mpidrEl1": {
             "type": "integer"
         },
+        "affinity3": {
+            "type": "integer"
+        },
         "midrEl1": {
             "type": "integer"
         },