diff --git a/ecs-logging-core/src/main/java/co/elastic/logging/EcsJsonSerializer.java b/ecs-logging-core/src/main/java/co/elastic/logging/EcsJsonSerializer.java
index 20312b38..6cf400aa 100644
--- a/ecs-logging-core/src/main/java/co/elastic/logging/EcsJsonSerializer.java
+++ b/ecs-logging-core/src/main/java/co/elastic/logging/EcsJsonSerializer.java
@@ -142,19 +142,23 @@ public static void serializeOrigin(StringBuilder builder, StackTraceElement stac
     }
 
     public static void serializeOrigin(StringBuilder builder, String fileName, String methodName, int lineNumber) {
-        builder.append("\"log.origin\":{");
-        builder.append("\"file.name\":\"");
+        builder.append("\"log\":{");
+        builder.append("\"origin\":{");
+        builder.append("\"file\":{");
+        builder.append("\"name\":\"");
         JsonUtils.quoteAsString(fileName, builder);
-        builder.append("\",");
-        builder.append("\"function\":\"");
-        JsonUtils.quoteAsString(methodName, builder);
         builder.append('"');
         if (lineNumber >= 0) {
             builder.append(',');
-            builder.append("\"file.line\":");
+            builder.append("\"line\":");
             builder.append(lineNumber);
         }
         builder.append("},");
+        builder.append("\"function\":\"");
+        JsonUtils.quoteAsString(methodName, builder);
+        builder.append('"');
+        builder.append("}");
+        builder.append("},");
     }
 
     public static void serializeMDC(StringBuilder builder, Map<String, ?> properties) {
diff --git a/ecs-logging-core/src/test/java/co/elastic/logging/AbstractEcsLoggingTest.java b/ecs-logging-core/src/test/java/co/elastic/logging/AbstractEcsLoggingTest.java
index b5b53c86..653c5073 100644
--- a/ecs-logging-core/src/test/java/co/elastic/logging/AbstractEcsLoggingTest.java
+++ b/ecs-logging-core/src/test/java/co/elastic/logging/AbstractEcsLoggingTest.java
@@ -37,8 +37,6 @@
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
-import java.util.stream.Collectors;
-import java.util.stream.StreamSupport;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatCode;
@@ -92,20 +90,30 @@ void validateLog(JsonNode logLine) {
             String specFieldName = specField.getKey();
             JsonNode specForField = specField.getValue();
             JsonNode fieldInLog = logLine.get(specFieldName);
+            if (fieldInLog == null) {
+                fieldInLog = logLine.at("/" + specFieldName.replace('.', '/'));
+            }
 
-            validateRequiredField(logLine, specFieldName, specForField.get("required").booleanValue());
-            if (fieldInLog != null) {
+            validateRequiredField(logLine, specFieldName, fieldInLog, specForField.get("required").booleanValue());
+            if (!fieldInLog.isMissingNode()) {
                 validateIndex(logLine, logFieldNames, specFieldName, specForField.get("index"));
                 validateType(fieldInLog, specForField.get("type").textValue());
+                validateNesting(logLine, specFieldName, specForField.has("top_level_field") && specForField.get("top_level_field").asBoolean(false));
             }
         }
     }
 
-    private void validateRequiredField(JsonNode logLine, String specFieldName, boolean required) {
+    private void validateNesting(JsonNode logLine, String specFieldName, boolean topLevelField) {
+        if (topLevelField) {
+            assertThat(logLine.at("/" + specFieldName.replace('.', '/')).isMissingNode()).isTrue();
+        }
+    }
+
+    private void validateRequiredField(JsonNode logLine, String specFieldName, JsonNode fieldInLog, boolean required) {
         if (required) {
-            assertThat(logLine.get(specFieldName))
-                    .describedAs(logLine.toString())
-                    .isNotNull();
+            assertThat(fieldInLog.isMissingNode())
+                    .describedAs("Expected %s to be non-null: %s", specFieldName, logLine)
+                    .isFalse();
         }
     }
 
@@ -196,9 +204,9 @@ void testLogExceptionNullMessage() throws Exception {
     @Test
     void testLogOrigin() throws Exception {
         debug("test");
-        assertThat(getAndValidateLastLogLine().get("log.origin").get("file.name").textValue()).endsWith(".java");
-        assertThat(getAndValidateLastLogLine().get("log.origin").get("function").textValue()).isEqualTo("debug");
-        assertThat(getAndValidateLastLogLine().get("log.origin").get("file.line").intValue()).isPositive();
+        assertThat(getAndValidateLastLogLine().at("/log/origin/file/name").textValue()).endsWith(".java");
+        assertThat(getAndValidateLastLogLine().at("/log/origin/function").textValue()).isEqualTo("debug");
+        assertThat(getAndValidateLastLogLine().at("/log/origin/file/line").intValue()).isPositive();
     }
 
     public boolean putMdc(String key, String value) {
diff --git a/ecs-logging-core/src/test/resources/spec/spec.json b/ecs-logging-core/src/test/resources/spec/spec.json
index d1b88d42..6fc077da 100644
--- a/ecs-logging-core/src/test/resources/spec/spec.json
+++ b/ecs-logging-core/src/test/resources/spec/spec.json
@@ -15,8 +15,15 @@
       "type": "string",
       "required": true,
       "index": 1,
-      "nesting_allowed": false,
-      "url": "https://www.elastic.co/guide/en/ecs/current/ecs-log.html"
+      "top_level_field": true,
+      "url": "https://www.elastic.co/guide/en/ecs/current/ecs-log.html",
+      "comment": [
+        "This field SHOULD NOT be a nested object field but at the top level with a dot in the property name.",
+        "This is to make the JSON logs more human-readable.",
+        "Loggers MAY indent the log level so that the `message` field always starts at the exact same offset,",
+        "no matter the number of characters the log level has.",
+        "For example: `'DEBUG'` (5 chars) will not be indented, whereas ` 'WARN'` (4 chars) will be indented by one space character."
+      ]
     },
     "message": {
       "type": "string",
diff --git a/jul-ecs-formatter/src/test/java/co/elastic/logging/jul/EcsFormatterTest.java b/jul-ecs-formatter/src/test/java/co/elastic/logging/jul/EcsFormatterTest.java
index bdf91894..464a1f6f 100644
--- a/jul-ecs-formatter/src/test/java/co/elastic/logging/jul/EcsFormatterTest.java
+++ b/jul-ecs-formatter/src/test/java/co/elastic/logging/jul/EcsFormatterTest.java
@@ -24,16 +24,16 @@
  */
 package co.elastic.logging.jul;
 
-import static org.assertj.core.api.Assertions.assertThat;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 
 import java.time.Instant;
 import java.util.logging.Level;
 import java.util.logging.LogRecord;
 
-import com.fasterxml.jackson.databind.JsonNode;
-import com.fasterxml.jackson.databind.ObjectMapper;
-import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Test;
+import static org.assertj.core.api.Assertions.assertThat;
 
 public class EcsFormatterTest {
 
@@ -57,8 +57,8 @@ public void testFormatWithIncludeOriginFlag() throws Exception {
 
         final String result = formatter.format(record);
 
-        assertThat(objectMapper.readTree(result).get("log.origin").get("file.name").textValue()).isEqualTo("ExampleClass.java");
-        assertThat(objectMapper.readTree(result).get("log.origin").get("function").textValue()).isEqualTo("exampleMethod");
+        assertThat(objectMapper.readTree(result).at("/log/origin/file/name").textValue()).isEqualTo("ExampleClass.java");
+        assertThat(objectMapper.readTree(result).at("/log/origin/function").textValue()).isEqualTo("exampleMethod");
     }
 
     @Test
@@ -91,8 +91,8 @@ public void testFormatWithInnerClassName() throws Exception {
         record.setSourceClassName("test.ExampleClass$InnerClass");
 
         JsonNode result = objectMapper.readTree(formatter.format(record));
-        assertThat(result.get("log.origin").get("file.name").textValue()).isEqualTo("ExampleClass.java");
-        assertThat(result.get("log.origin").get("function").textValue()).isEqualTo("exampleMethod");
+        assertThat(result.at("/log/origin/file/name").textValue()).isEqualTo("ExampleClass.java");
+        assertThat(result.at("/log/origin/function").textValue()).isEqualTo("exampleMethod");
     }
 
     @Test
@@ -101,8 +101,8 @@ public void testFormatWithInvalidClassName() throws Exception {
         record.setSourceClassName("$test.ExampleClass");
 
         JsonNode result = objectMapper.readTree(formatter.format(record));
-        assertThat(result.get("log.origin").get("file.name").textValue()).isEqualTo("<Unknown>");
-        assertThat(result.get("log.origin").get("function").textValue()).isEqualTo("exampleMethod");
+        assertThat(result.at("/log/origin/file/name").textValue()).isEqualTo("<Unknown>");
+        assertThat(result.at("/log/origin/function").textValue()).isEqualTo("exampleMethod");
     }
 
 }
diff --git a/jul-ecs-formatter/src/test/java/co/elastic/logging/jul/JulLoggingTest.java b/jul-ecs-formatter/src/test/java/co/elastic/logging/jul/JulLoggingTest.java
index 50630fa1..37887492 100644
--- a/jul-ecs-formatter/src/test/java/co/elastic/logging/jul/JulLoggingTest.java
+++ b/jul-ecs-formatter/src/test/java/co/elastic/logging/jul/JulLoggingTest.java
@@ -40,8 +40,6 @@
 import java.util.logging.LogRecord;
 import java.util.logging.Logger;
 import java.util.logging.StreamHandler;
-import java.util.stream.Collectors;
-import java.util.stream.StreamSupport;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -127,8 +125,8 @@ void setUp() {
     @Test
     void testLogOrigin() throws Exception {
         debug("test");
-        assertThat(getAndValidateLastLogLine().get("log.origin").get("file.name").textValue()).endsWith(".java");
-        assertThat(getAndValidateLastLogLine().get("log.origin").get("function").textValue()).isEqualTo("debug");
+        assertThat(getAndValidateLastLogLine().at("/log/origin/file/name").textValue()).endsWith(".java");
+        assertThat(getAndValidateLastLogLine().at("/log/origin/function").textValue()).isEqualTo("debug");
         //No file.line for JUL
     }