diff --git a/core/spring-boot/src/main/java/org/springframework/boot/logging/logback/ElasticCommonSchemaStructuredLogFormatter.java b/core/spring-boot/src/main/java/org/springframework/boot/logging/logback/ElasticCommonSchemaStructuredLogFormatter.java
index 0aa703ed98b..aa4fb77379e 100644
--- a/core/spring-boot/src/main/java/org/springframework/boot/logging/logback/ElasticCommonSchemaStructuredLogFormatter.java
+++ b/core/spring-boot/src/main/java/org/springframework/boot/logging/logback/ElasticCommonSchemaStructuredLogFormatter.java
@@ -100,6 +100,7 @@ class ElasticCommonSchemaStructuredLogFormatter extends JsonWriterStructuredLogF
 		return result;
 	}
 
+	@SuppressWarnings("deprecation")
 	private static void addMarkers(Set<String> result, Iterator<Marker> iterator) {
 		while (iterator.hasNext()) {
 			Marker marker = iterator.next();
diff --git a/core/spring-boot/src/main/java/org/springframework/boot/logging/logback/LogstashStructuredLogFormatter.java b/core/spring-boot/src/main/java/org/springframework/boot/logging/logback/LogstashStructuredLogFormatter.java
index d4927b0c4a8..9ff822d3673 100644
--- a/core/spring-boot/src/main/java/org/springframework/boot/logging/logback/LogstashStructuredLogFormatter.java
+++ b/core/spring-boot/src/main/java/org/springframework/boot/logging/logback/LogstashStructuredLogFormatter.java
@@ -93,6 +93,7 @@ class LogstashStructuredLogFormatter extends JsonWriterStructuredLogFormatter<IL
 		return result;
 	}
 
+	@SuppressWarnings("deprecation")
 	private static void addMarkers(Set<String> result, Iterator<Marker> iterator) {
 		while (iterator.hasNext()) {
 			Marker marker = iterator.next();
diff --git a/core/spring-boot/src/test/java/org/springframework/boot/logging/logback/ElasticCommonSchemaStructuredLogFormatterTests.java b/core/spring-boot/src/test/java/org/springframework/boot/logging/logback/ElasticCommonSchemaStructuredLogFormatterTests.java
index 529e3606d88..2264c12ff62 100644
--- a/core/spring-boot/src/test/java/org/springframework/boot/logging/logback/ElasticCommonSchemaStructuredLogFormatterTests.java
+++ b/core/spring-boot/src/test/java/org/springframework/boot/logging/logback/ElasticCommonSchemaStructuredLogFormatterTests.java
@@ -134,6 +134,19 @@ class ElasticCommonSchemaStructuredLogFormatterTests extends AbstractStructuredL
 
 	@Test
 	void shouldFormatMarkersAsTags() {
+		LoggingEvent event = createEvent();
+		event.setMDCPropertyMap(Collections.emptyMap());
+		event.addMarker(MarkerFactory.getDetachedMarker("marker-1"));
+		event.addMarker(MarkerFactory.getDetachedMarker("marker-2"));
+		event.addMarker(MarkerFactory.getDetachedMarker("marker-3"));
+		String json = this.formatter.format(event);
+		Map<String, Object> deserialized = deserialize(json);
+		assertThat(deserialized.get("tags")).isEqualTo(List.of("marker-1", "marker-2", "marker-3"));
+	}
+
+	@Test
+	@SuppressWarnings("deprecation")
+	void shouldFormatNestedMarkersAsTags() {
 		LoggingEvent event = createEvent();
 		event.setMDCPropertyMap(Collections.emptyMap());
 		Marker parent = MarkerFactory.getDetachedMarker("parent");
diff --git a/core/spring-boot/src/test/java/org/springframework/boot/logging/logback/LogstashStructuredLogFormatterTests.java b/core/spring-boot/src/test/java/org/springframework/boot/logging/logback/LogstashStructuredLogFormatterTests.java
index 835b1ad07a4..dd74b366128 100644
--- a/core/spring-boot/src/test/java/org/springframework/boot/logging/logback/LogstashStructuredLogFormatterTests.java
+++ b/core/spring-boot/src/test/java/org/springframework/boot/logging/logback/LogstashStructuredLogFormatterTests.java
@@ -62,6 +62,23 @@ class LogstashStructuredLogFormatterTests extends AbstractStructuredLoggingTests
 		LoggingEvent event = createEvent();
 		event.setMDCPropertyMap(Map.of("mdc-1", "mdc-v-1"));
 		event.setKeyValuePairs(keyValuePairs("kv-1", "kv-v-1"));
+		event.addMarker(getMarker("marker-1"));
+		event.addMarker(getMarker("marker-2"));
+		String json = this.formatter.format(event);
+		assertThat(json).endsWith("\n");
+		Map<String, Object> deserialized = deserialize(json);
+		String timestamp = DateTimeFormatter.ISO_OFFSET_DATE_TIME
+			.format(OffsetDateTime.ofInstant(EVENT_TIME, ZoneId.systemDefault()));
+		assertThat(deserialized).containsExactlyInAnyOrderEntriesOf(map("@timestamp", timestamp, "@version", "1",
+				"message", "message", "logger_name", "org.example.Test", "thread_name", "main", "level", "INFO",
+				"level_value", 20000, "mdc-1", "mdc-v-1", "kv-1", "kv-v-1", "tags", List.of("marker-1", "marker-2")));
+	}
+
+	@Test
+	@SuppressWarnings("deprecation")
+	void shouldFormatWithNestedMarker() {
+		LoggingEvent event = createEvent();
+		event.setMDCPropertyMap(Map.of("mdc-1", "mdc-v-1"));
 		Marker marker1 = getMarker("marker-1");
 		marker1.add(getMarker("marker-2"));
 		event.addMarker(marker1);
@@ -72,7 +89,7 @@ class LogstashStructuredLogFormatterTests extends AbstractStructuredLoggingTests
 			.format(OffsetDateTime.ofInstant(EVENT_TIME, ZoneId.systemDefault()));
 		assertThat(deserialized).containsExactlyInAnyOrderEntriesOf(map("@timestamp", timestamp, "@version", "1",
 				"message", "message", "logger_name", "org.example.Test", "thread_name", "main", "level", "INFO",
-				"level_value", 20000, "mdc-1", "mdc-v-1", "kv-1", "kv-v-1", "tags", List.of("marker-1", "marker-2")));
+				"level_value", 20000, "mdc-1", "mdc-v-1", "tags", List.of("marker-1", "marker-2")));
 	}
 
 	@Test
diff --git a/platform/spring-boot-dependencies/build.gradle b/platform/spring-boot-dependencies/build.gradle
index c93cdde679c..7c5a2082382 100644
--- a/platform/spring-boot-dependencies/build.gradle
+++ b/platform/spring-boot-dependencies/build.gradle
@@ -2479,7 +2479,7 @@ bom {
 			releaseNotes("https://github.com/sendgrid/sendgrid-java/releases/tag/{version}")
 		}
 	}
-	library("SLF4J", "2.0.18") {
+	library("SLF4J", "2.0.20") {
 		prohibit {
 			contains "-alpha"
 			because "we don't want alphas"