diff --git a/CHANGELOG.md b/CHANGELOG.md
index d34a35cbd7..009ca7ae7d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,6 @@
 # CHANGELOG
 Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
-## [Unreleased]
+## [Unreleased 2.x](https://github.com/opensearch-project/opensearch-java/compare/v2.6.0...2.x)
 ### Added
 
 ### Dependencies
@@ -16,6 +16,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Remove generated code comments from all files ([#598](https://github.com/opensearch-project/opensearch-java/pull/598))
 
 ### Fixed
+- Fix PutMappingRequest by removing unsupported fields ([#597](https://github.com/opensearch-project/opensearch-java/pull/597))
 
 ### Security
 
diff --git a/java-client/src/main/java/org/opensearch/client/opensearch/indices/PutMappingRequest.java b/java-client/src/main/java/org/opensearch/client/opensearch/indices/PutMappingRequest.java
index 53d45e8193..99b2951846 100644
--- a/java-client/src/main/java/org/opensearch/client/opensearch/indices/PutMappingRequest.java
+++ b/java-client/src/main/java/org/opensearch/client/opensearch/indices/PutMappingRequest.java
@@ -115,8 +115,6 @@ public class PutMappingRequest extends RequestBase implements JsonpSerializable
 
 	private final Map<String, Property> properties;
 
-	private final Map<String, RuntimeField> runtime;
-
 	@Nullable
 	private final Time timeout;
 
@@ -143,7 +141,6 @@ private PutMappingRequest(Builder builder) {
 		this.clusterManagerTimeout = builder.clusterManagerTimeout;
 		this.numericDetection = builder.numericDetection;
 		this.properties = ApiTypeHelper.unmodifiable(builder.properties);
-		this.runtime = ApiTypeHelper.unmodifiable(builder.runtime);
 		this.timeout = builder.timeout;
 		this.writeIndexOnly = builder.writeIndexOnly;
 
@@ -323,15 +320,6 @@ public final Map<String, Property> properties() {
 		return this.properties;
 	}
 
-	/**
-	 * Mapping of runtime fields for the index.
-	 * <p>
-	 * API name: {@code runtime}
-	 */
-	public final Map<String, RuntimeField> runtime() {
-		return this.runtime;
-	}
-
 	/**
 	 * Explicit operation timeout
 	 * <p>
@@ -443,18 +431,6 @@ protected void serializeInternal(JsonGenerator generator, JsonpMapper mapper) {
 			generator.writeEnd();
 
 		}
-		if (ApiTypeHelper.isDefined(this.runtime)) {
-			generator.writeKey("runtime");
-			generator.writeStartObject();
-			for (Map.Entry<String, RuntimeField> item0 : this.runtime.entrySet()) {
-				generator.writeKey(item0.getKey());
-				item0.getValue().serialize(generator, mapper);
-
-			}
-			generator.writeEnd();
-
-		}
-
 	}
 
 	// ---------------------------------------------------------------------------------------------
@@ -512,9 +488,6 @@ public static class Builder extends ObjectBuilderBase implements ObjectBuilder<P
 		@Nullable
 		private Map<String, Property> properties;
 
-		@Nullable
-		private Map<String, RuntimeField> runtime;
-
 		@Nullable
 		private Time timeout;
 
@@ -856,41 +829,6 @@ public final Builder properties(String key, Function<Property.Builder, ObjectBui
 			return properties(key, fn.apply(new Property.Builder()).build());
 		}
 
-		/**
-		 * Mapping of runtime fields for the index.
-		 * <p>
-		 * API name: {@code runtime}
-		 * <p>
-		 * Adds all entries of <code>map</code> to <code>runtime</code>.
-		 */
-		public final Builder runtime(Map<String, RuntimeField> map) {
-			this.runtime = _mapPutAll(this.runtime, map);
-			return this;
-		}
-
-		/**
-		 * Mapping of runtime fields for the index.
-		 * <p>
-		 * API name: {@code runtime}
-		 * <p>
-		 * Adds an entry to <code>runtime</code>.
-		 */
-		public final Builder runtime(String key, RuntimeField value) {
-			this.runtime = _mapPut(this.runtime, key, value);
-			return this;
-		}
-
-		/**
-		 * Mapping of runtime fields for the index.
-		 * <p>
-		 * API name: {@code runtime}
-		 * <p>
-		 * Adds an entry to <code>runtime</code> using a builder lambda.
-		 */
-		public final Builder runtime(String key, Function<RuntimeField.Builder, ObjectBuilder<RuntimeField>> fn) {
-			return runtime(key, fn.apply(new RuntimeField.Builder()).build());
-		}
-
 		/**
 		 * Explicit operation timeout
 		 * <p>
@@ -956,8 +894,6 @@ protected static void setupPutMappingRequestDeserializer(ObjectDeserializer<PutM
 				JsonpDeserializer.stringMapDeserializer(DynamicTemplate._DESERIALIZER)), "dynamic_templates");
 		op.add(Builder::numericDetection, JsonpDeserializer.booleanDeserializer(), "numeric_detection");
 		op.add(Builder::properties, JsonpDeserializer.stringMapDeserializer(Property._DESERIALIZER), "properties");
-		op.add(Builder::runtime, JsonpDeserializer.stringMapDeserializer(RuntimeField._DESERIALIZER), "runtime");
-
 	}
 
 	// ---------------------------------------------------------------------------------------------