diff --git a/src/npdmtool.c b/src/npdmtool.c
index 866ccec..cca5398 100644
--- a/src/npdmtool.c
+++ b/src/npdmtool.c
@@ -76,7 +76,8 @@ typedef struct {
     u8 _0xD;
     u8 MainThreadPriority;
     u8 DefaultCpuId;
-    u64 _0x10;
+    u32 _0x10;
+    u32 SystemResourceSize;
     u32 ProcessCategory;
     u32 MainThreadStackSize;
     char Name[0x10];
@@ -219,6 +220,32 @@ int cJSON_GetU64(const cJSON *obj, const char *field, u64 *out) {
     }
 }
 
+int cJSON_GetU32(const cJSON *obj, const char *field, u32 *out) {
+    const cJSON *config = cJSON_GetObjectItemCaseSensitive(obj, field);
+    if (cJSON_IsString(config) && (config->valuestring != NULL)) {
+        char *endptr = NULL;
+        *out = strtoul(config->valuestring, &endptr, 16);
+        if (config->valuestring == endptr) {
+            fprintf(stderr, "Failed to get %s (empty string)\n", field);
+            return 0;
+        } else if (errno == ERANGE) {
+            fprintf(stderr, "Failed to get %s (value out of range)\n", field);
+            return 0;
+        } else if (errno == EINVAL) {
+            fprintf(stderr, "Failed to get %s (not base16 string)\n", field);
+            return 0;
+        } else if (errno) {
+            fprintf(stderr, "Failed to get %s (unknown error)\n", field);
+            return 0;
+        } else {
+            return 1;
+        }
+    } else {
+        fprintf(stderr, "Failed to get %s (field not present).\n", field);
+        return 0;
+    }
+}
+
 int cJSON_GetU64FromObjectValue(const cJSON *config, u64 *out) {
     if (cJSON_IsString(config) && (config->valuestring != NULL)) {
         char *endptr = NULL;
@@ -305,6 +332,9 @@ int CreateNpdm(const char *json, void **dst, u32 *dst_size) {
         status = 0;
         goto NPDM_BUILD_END;
     }
+
+    cJSON_GetU32(npdm_json, "system_resource_size", &header.SystemResourceSize); // optional
+
     if (!cJSON_GetU8(npdm_json, "process_category", (u8 *)&header.ProcessCategory)) {
         status = 0;
         goto NPDM_BUILD_END;