diff --git a/sections/cper-section-pci-dev.c b/sections/cper-section-pci-dev.c
index ccf9f0c..8dc899b 100644
--- a/sections/cper-section-pci-dev.c
+++ b/sections/cper-section-pci-dev.c
@@ -18,67 +18,85 @@
 	json_object *section_ir = json_object_new_object();
 
 	//Validation bits.
-	json_object *validation = bitfield_to_ir(
-		dev_error->ValidFields, 5, PCI_DEV_ERROR_VALID_BITFIELD_NAMES);
-	json_object_object_add(section_ir, "validationBits", validation);
+	ValidationTypes ui64Type = { UINT_64T,
+				     .value.ui64 = dev_error->ValidFields };
 
 	//Error status.
-	json_object *error_status =
-		cper_generic_error_status_to_ir(&dev_error->ErrorStatus);
-	json_object_object_add(section_ir, "errorStatus", error_status);
+	if (isvalid_prop_to_ir(&ui64Type, 0)) {
+		json_object *error_status = cper_generic_error_status_to_ir(
+			&dev_error->ErrorStatus);
+		json_object_object_add(section_ir, "errorStatus", error_status);
+	}
 
 	//ID information.
-	json_object *id_info = json_object_new_object();
-	json_object_object_add(
-		id_info, "vendorID",
-		json_object_new_uint64(dev_error->IdInfo.VendorId));
-	json_object_object_add(
-		id_info, "deviceID",
-		json_object_new_uint64(dev_error->IdInfo.DeviceId));
-	json_object_object_add(
-		id_info, "classCode",
-		json_object_new_uint64(dev_error->IdInfo.ClassCode));
-	json_object_object_add(
-		id_info, "functionNumber",
-		json_object_new_uint64(dev_error->IdInfo.FunctionNumber));
-	json_object_object_add(
-		id_info, "deviceNumber",
-		json_object_new_uint64(dev_error->IdInfo.DeviceNumber));
-	json_object_object_add(
-		id_info, "busNumber",
-		json_object_new_uint64(dev_error->IdInfo.BusNumber));
-	json_object_object_add(
-		id_info, "segmentNumber",
-		json_object_new_uint64(dev_error->IdInfo.SegmentNumber));
-	json_object_object_add(section_ir, "idInfo", id_info);
+	if (isvalid_prop_to_ir(&ui64Type, 1)) {
+		json_object *id_info = json_object_new_object();
+		json_object_object_add(
+			id_info, "vendorID",
+			json_object_new_uint64(dev_error->IdInfo.VendorId));
+		json_object_object_add(
+			id_info, "deviceID",
+			json_object_new_uint64(dev_error->IdInfo.DeviceId));
+		json_object_object_add(
+			id_info, "classCode",
+			json_object_new_uint64(dev_error->IdInfo.ClassCode));
+		json_object_object_add(
+			id_info, "functionNumber",
+			json_object_new_uint64(
+				dev_error->IdInfo.FunctionNumber));
+		json_object_object_add(
+			id_info, "deviceNumber",
+			json_object_new_uint64(dev_error->IdInfo.DeviceNumber));
+		json_object_object_add(
+			id_info, "busNumber",
+			json_object_new_uint64(dev_error->IdInfo.BusNumber));
+		json_object_object_add(
+			id_info, "segmentNumber",
+			json_object_new_uint64(
+				dev_error->IdInfo.SegmentNumber));
+		json_object_object_add(section_ir, "idInfo", id_info);
+	}
 
 	//Number of following register data pairs.
-	json_object_object_add(section_ir, "memoryNumber",
-			       json_object_new_uint64(dev_error->MemoryNumber));
-	json_object_object_add(section_ir, "ioNumber",
-			       json_object_new_uint64(dev_error->IoNumber));
-	int num_data_pairs = dev_error->MemoryNumber + dev_error->IoNumber;
-
-	//Register pairs, described by the numeric fields.
-	//The actual "pairs" of address and data aren't necessarily 8 bytes long, so can't assume the contents.
-	//Hence the naming "firstHalf" and "secondHalf" rather than "address" and "data".
-	json_object *register_data_pair_array = json_object_new_array();
-	UINT64 *cur_pos = (UINT64 *)(dev_error + 1);
-	for (int i = 0; i < num_data_pairs; i++) {
-		//Save current pair to array.
-		json_object *register_data_pair = json_object_new_object();
-		json_object_object_add(register_data_pair, "firstHalf",
-				       json_object_new_uint64(*cur_pos));
-		json_object_object_add(register_data_pair, "secondHalf",
-				       json_object_new_uint64(*(cur_pos + 1)));
-		json_object_array_add(register_data_pair_array,
-				      register_data_pair);
-
-		//Move to next pair.
-		cur_pos += 2;
+	if (isvalid_prop_to_ir(&ui64Type, 2)) {
+		json_object_object_add(
+			section_ir, "memoryNumber",
+			json_object_new_uint64(dev_error->MemoryNumber));
 	}
-	json_object_object_add(section_ir, "registerDataPairs",
-			       register_data_pair_array);
+	if (isvalid_prop_to_ir(&ui64Type, 3)) {
+		json_object_object_add(
+			section_ir, "ioNumber",
+			json_object_new_uint64(dev_error->IoNumber));
+	}
+
+	if (isvalid_prop_to_ir(&ui64Type, 4)) {
+		int num_data_pairs =
+			dev_error->MemoryNumber + dev_error->IoNumber;
+
+		//Register pairs, described by the numeric fields.
+		//The actual "pairs" of address and data aren't necessarily 8 bytes long, so can't assume the contents.
+		//Hence the naming "firstHalf" and "secondHalf" rather than "address" and "data".
+		json_object *register_data_pair_array = json_object_new_array();
+		UINT64 *cur_pos = (UINT64 *)(dev_error + 1);
+		for (int i = 0; i < num_data_pairs; i++) {
+			//Save current pair to array.
+			json_object *register_data_pair =
+				json_object_new_object();
+			json_object_object_add(
+				register_data_pair, "firstHalf",
+				json_object_new_uint64(*cur_pos));
+			json_object_object_add(
+				register_data_pair, "secondHalf",
+				json_object_new_uint64(*(cur_pos + 1)));
+			json_object_array_add(register_data_pair_array,
+					      register_data_pair);
+
+			//Move to next pair.
+			cur_pos += 2;
+		}
+		json_object_object_add(section_ir, "registerDataPairs",
+				       register_data_pair_array);
+	}
 
 	return section_ir;
 }
@@ -90,37 +108,53 @@
 			1, sizeof(EFI_PCI_PCIX_DEVICE_ERROR_DATA));
 
 	//Validation bits.
-	section_cper->ValidFields = ir_to_bitfield(
-		json_object_object_get(section, "validationBits"), 5,
-		PCI_DEV_ERROR_VALID_BITFIELD_NAMES);
+	ValidationTypes ui64Type = { UINT_64T, .value.ui64 = 0 };
+	struct json_object *obj = NULL;
 
 	//Error status.
-	ir_generic_error_status_to_cper(json_object_object_get(section,
-							       "errorStatus"),
-					&section_cper->ErrorStatus);
+	if (json_object_object_get_ex(section, "errorStatus", &obj)) {
+		ir_generic_error_status_to_cper(obj,
+						&section_cper->ErrorStatus);
+		add_to_valid_bitfield(&ui64Type, 0);
+	}
 
 	//Device ID information.
-	json_object *id_info = json_object_object_get(section, "idInfo");
-	section_cper->IdInfo.VendorId = json_object_get_uint64(
-		json_object_object_get(id_info, "vendorID"));
-	section_cper->IdInfo.DeviceId = json_object_get_uint64(
-		json_object_object_get(id_info, "deviceID"));
-	section_cper->IdInfo.ClassCode = json_object_get_uint64(
-		json_object_object_get(id_info, "classCode"));
-	section_cper->IdInfo.FunctionNumber = json_object_get_uint64(
-		json_object_object_get(id_info, "functionNumber"));
-	section_cper->IdInfo.DeviceNumber = json_object_get_uint64(
-		json_object_object_get(id_info, "deviceNumber"));
-	section_cper->IdInfo.BusNumber = json_object_get_uint64(
-		json_object_object_get(id_info, "busNumber"));
-	section_cper->IdInfo.SegmentNumber = json_object_get_uint64(
-		json_object_object_get(id_info, "segmentNumber"));
+	if (json_object_object_get_ex(section, "idInfo", &obj)) {
+		json_object *id_info = obj;
+		section_cper->IdInfo.VendorId = json_object_get_uint64(
+			json_object_object_get(id_info, "vendorID"));
+		section_cper->IdInfo.DeviceId = json_object_get_uint64(
+			json_object_object_get(id_info, "deviceID"));
+		section_cper->IdInfo.ClassCode = json_object_get_uint64(
+			json_object_object_get(id_info, "classCode"));
+		section_cper->IdInfo.FunctionNumber = json_object_get_uint64(
+			json_object_object_get(id_info, "functionNumber"));
+		section_cper->IdInfo.DeviceNumber = json_object_get_uint64(
+			json_object_object_get(id_info, "deviceNumber"));
+		section_cper->IdInfo.BusNumber = json_object_get_uint64(
+			json_object_object_get(id_info, "busNumber"));
+		section_cper->IdInfo.SegmentNumber = json_object_get_uint64(
+			json_object_object_get(id_info, "segmentNumber"));
+		add_to_valid_bitfield(&ui64Type, 1);
+	}
 
 	//Amount of following data pairs.
-	section_cper->MemoryNumber = (UINT32)json_object_get_uint64(
-		json_object_object_get(section, "memoryNumber"));
-	section_cper->IoNumber = (UINT32)json_object_get_uint64(
-		json_object_object_get(section, "ioNumber"));
+	if (json_object_object_get_ex(section, "memoryNumber", &obj)) {
+		section_cper->MemoryNumber =
+			(UINT32)json_object_get_uint64(obj);
+		add_to_valid_bitfield(&ui64Type, 2);
+	}
+	if (json_object_object_get_ex(section, "ioNumber", &obj)) {
+		section_cper->IoNumber = (UINT32)json_object_get_uint64(obj);
+		add_to_valid_bitfield(&ui64Type, 3);
+	}
+	json_object *register_pairs = NULL;
+	if (json_object_object_get_ex(section, "registerDataPairs", &obj)) {
+		register_pairs = obj;
+		add_to_valid_bitfield(&ui64Type, 4);
+	}
+
+	section_cper->ValidFields = ui64Type.value.ui64;
 
 	//Write header out to stream, free it.
 	fwrite(section_cper, sizeof(EFI_PCI_PCIX_DEVICE_ERROR_DATA), 1, out);
@@ -128,23 +162,23 @@
 	free(section_cper);
 
 	//Begin writing register pairs.
-	json_object *register_pairs =
-		json_object_object_get(section, "registerDataPairs");
-	int num_pairs = json_object_array_length(register_pairs);
-	for (int i = 0; i < num_pairs; i++) {
-		//Get the pair array item out.
-		json_object *register_pair =
-			json_object_array_get_idx(register_pairs, i);
+	if (register_pairs != NULL) {
+		int num_pairs = json_object_array_length(register_pairs);
+		for (int i = 0; i < num_pairs; i++) {
+			//Get the pair array item out.
+			json_object *register_pair =
+				json_object_array_get_idx(register_pairs, i);
 
-		//Create the pair array.
-		UINT64 pair[2];
-		pair[0] = json_object_get_uint64(
-			json_object_object_get(register_pair, "firstHalf"));
-		pair[1] = json_object_get_uint64(
-			json_object_object_get(register_pair, "secondHalf"));
+			//Create the pair array.
+			UINT64 pair[2];
+			pair[0] = json_object_get_uint64(json_object_object_get(
+				register_pair, "firstHalf"));
+			pair[1] = json_object_get_uint64(json_object_object_get(
+				register_pair, "secondHalf"));
 
-		//Push to stream.
-		fwrite(pair, sizeof(UINT64), 2, out);
-		fflush(out);
+			//Push to stream.
+			fwrite(pair, sizeof(UINT64), 2, out);
+			fflush(out);
+		}
 	}
 }