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 deb77a15..8492e629 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
@@ -46,7 +46,7 @@ public static void serializeObjectStart(StringBuilder builder, long timeMillis)
         builder.append('{');
         builder.append("\"@timestamp\":\"");
         TIMESTAMP_SERIALIZER.serializeEpochTimestampAsIsoDateTime(builder, timeMillis);
-        builder.append("\", ");
+        builder.append("\",");
     }
 
     public static void serializeEcsVersion(StringBuilder builder) {
@@ -84,7 +84,7 @@ public static void serializeThreadId(StringBuilder builder, long threadId) {
     public static void serializeFormattedMessage(StringBuilder builder, String message) {
         builder.append("\"message\":\"");
         JsonUtils.quoteAsString(message, builder);
-        builder.append("\", ");
+        builder.append("\",");
     }
 
     public static void serializeServiceName(StringBuilder builder, String serviceName) {
@@ -121,7 +121,7 @@ public static void serializeLogLevel(StringBuilder builder, String level) {
         }
         builder.append('\"');
         JsonUtils.quoteAsString(level, builder);
-        builder.append("\", ");
+        builder.append("\",");
     }
 
     public static void serializeTag(StringBuilder builder, String tag) {
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 8358570e..671acc3d 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
@@ -55,23 +55,27 @@ final void setUpSpec() throws Exception {
     @Test
     void testMetadata() throws Exception {
         debug("test");
-        assertThat(getAndValidateLastLogLine().get("process.thread.name").textValue()).isEqualTo(Thread.currentThread().getName());
-        assertThat(getAndValidateLastLogLine().get("service.name").textValue()).isEqualTo("test");
-        assertThat(getAndValidateLastLogLine().get("service.node.name").textValue()).isEqualTo("test-node");
-        assertThat(Instant.parse(getAndValidateLastLogLine().get("@timestamp").textValue())).isCloseTo(Instant.now(), within(1, ChronoUnit.MINUTES));
-        assertThat(getAndValidateLastLogLine().get("log.level").textValue()).isIn("DEBUG", "FINE");
-        assertThat(getAndValidateLastLogLine().get("log.logger")).isNotNull();
-        assertThat(getAndValidateLastLogLine().get("event.dataset").textValue()).isEqualTo("testdataset");
-        assertThat(getAndValidateLastLogLine().get("ecs.version").textValue()).isEqualTo("1.2.0");
-        validateLog(getAndValidateLastLogLine());
+        JsonNode logLine = getAndValidateLastLogLine();
+        System.out.println(logLine.toPrettyString());
+        assertThat(logLine.get("process.thread.name").textValue()).isEqualTo(Thread.currentThread().getName());
+        assertThat(logLine.get("service.name").textValue()).isEqualTo("test");
+        assertThat(logLine.get("service.node.name").textValue()).isEqualTo("test-node");
+        assertThat(Instant.parse(logLine.get("@timestamp").textValue())).isCloseTo(Instant.now(), within(1, ChronoUnit.MINUTES));
+        assertThat(logLine.get("log.level").textValue()).isIn("DEBUG", "FINE");
+        assertThat(logLine.get("log.logger")).isNotNull();
+        assertThat(logLine.get("event.dataset").textValue()).isEqualTo("testdataset");
+        assertThat(logLine.get("ecs.version").textValue()).isEqualTo("1.2.0");
+        validateLog(logLine);
     }
 
     @Test
     protected final void testAdditionalFields() throws Exception {
         debug("test");
-        assertThat(getAndValidateLastLogLine().get("key1").textValue()).isEqualTo("value1");
-        assertThat(getAndValidateLastLogLine().get("key2").textValue()).isEqualTo("value2");
-        validateLog(getAndValidateLastLogLine());
+        JsonNode logLine = getAndValidateLastLogLine();
+        System.out.println(logLine.toPrettyString());
+        assertThat(logLine.get("key1").textValue()).isEqualTo("value1");
+        assertThat(logLine.get("key2").textValue()).isEqualTo("value2");
+        validateLog(logLine);
     }
 
     @Test
@@ -189,6 +193,7 @@ void testMdc() throws Exception {
     void testLogException() throws Exception {
         error("test", new RuntimeException("test"));
         JsonNode log = getAndValidateLastLogLine();
+        System.out.println(log.toPrettyString());
         assertThat(log.get("log.level").textValue()).isIn("ERROR", "SEVERE");
         assertThat(log.get("error.message").textValue()).isEqualTo("test");
         assertThat(log.get("error.type").textValue()).isEqualTo(RuntimeException.class.getName());
@@ -205,9 +210,11 @@ void testLogExceptionNullMessage() throws Exception {
     @Test
     void testLogOrigin() throws Exception {
         debug("test");
-        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();
+        JsonNode logLine = getAndValidateLastLogLine();
+        System.out.println(logLine.toPrettyString());
+        assertThat(logLine.at("/log/origin/file/name").textValue()).endsWith(".java");
+        assertThat(logLine.at("/log/origin/function").textValue()).isEqualTo("debug");
+        assertThat(logLine.at("/log/origin/file/line").intValue()).isPositive();
     }
 
     public boolean putMdc(String key, String value) {
diff --git a/ecs-logging-core/src/test/java/co/elastic/logging/EcsJsonSerializerTest.java b/ecs-logging-core/src/test/java/co/elastic/logging/EcsJsonSerializerTest.java
index ec851e8a..0b96a38e 100644
--- a/ecs-logging-core/src/test/java/co/elastic/logging/EcsJsonSerializerTest.java
+++ b/ecs-logging-core/src/test/java/co/elastic/logging/EcsJsonSerializerTest.java
@@ -96,7 +96,7 @@ void testEscaping() throws IOException {
     void serializeNullDoesNotThrowAnException() throws JsonProcessingException {
         StringBuilder stringBuilder = new StringBuilder();
         EcsJsonSerializer.serializeFormattedMessage(stringBuilder, null);
-        assertThat(stringBuilder.toString()).isEqualTo("\"message\":\"null\", ");
+        assertThat(stringBuilder.toString()).isEqualTo("\"message\":\"null\",");
     }
 
     @Test