diff --git a/plugin/src/main/java/org/opensearch/ml/rest/RestMLUpdateConnectorAction.java b/plugin/src/main/java/org/opensearch/ml/rest/RestMLUpdateConnectorAction.java
index 2957740354..0c31695d1d 100644
--- a/plugin/src/main/java/org/opensearch/ml/rest/RestMLUpdateConnectorAction.java
+++ b/plugin/src/main/java/org/opensearch/ml/rest/RestMLUpdateConnectorAction.java
@@ -16,6 +16,7 @@
 import java.util.List;
 import java.util.Locale;
 
+import org.opensearch.OpenSearchParseException;
 import org.opensearch.client.node.NodeClient;
 import org.opensearch.core.xcontent.XContentParser;
 import org.opensearch.ml.common.transport.connector.MLUpdateConnectorAction;
@@ -63,14 +64,17 @@ private MLUpdateConnectorRequest getRequest(RestRequest request) throws IOExcept
             throw new IllegalStateException(UPDATE_CONNECTOR_DISABLED_ERR_MSG);
         }
         if (!request.hasContent()) {
-            throw new IOException("Failed to update connector: Request body is empty");
+            throw new OpenSearchParseException("Failed to update connector: Request body is empty");
         }
 
         String connectorId = getParameterId(request, PARAMETER_CONNECTOR_ID);
 
-        XContentParser parser = request.contentParser();
-        ensureExpectedToken(XContentParser.Token.START_OBJECT, parser.nextToken(), parser);
-
-        return MLUpdateConnectorRequest.parse(parser, connectorId);
+        try {
+            XContentParser parser = request.contentParser();
+            ensureExpectedToken(XContentParser.Token.START_OBJECT, parser.nextToken(), parser);
+            return MLUpdateConnectorRequest.parse(parser, connectorId);
+        } catch (IllegalStateException illegalStateException) {
+            throw new OpenSearchParseException(illegalStateException.getMessage());
+        }
     }
 }
diff --git a/plugin/src/test/java/org/opensearch/ml/rest/RestMLUpdateConnectorActionTests.java b/plugin/src/test/java/org/opensearch/ml/rest/RestMLUpdateConnectorActionTests.java
index 3bc5a5e940..d880baaa2e 100644
--- a/plugin/src/test/java/org/opensearch/ml/rest/RestMLUpdateConnectorActionTests.java
+++ b/plugin/src/test/java/org/opensearch/ml/rest/RestMLUpdateConnectorActionTests.java
@@ -14,7 +14,6 @@
 import static org.mockito.Mockito.when;
 import static org.opensearch.ml.utils.MLExceptionUtils.REMOTE_INFERENCE_DISABLED_ERR_MSG;
 
-import java.io.IOException;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -25,6 +24,7 @@
 import org.mockito.ArgumentCaptor;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
+import org.opensearch.OpenSearchParseException;
 import org.opensearch.action.update.UpdateResponse;
 import org.opensearch.client.node.NodeClient;
 import org.opensearch.common.settings.Settings;
@@ -114,8 +114,15 @@ public void testUpdateConnectorRequest() throws Exception {
         assertEquals("2", updateConnectorRequest.getUpdateContent().getVersion());
     }
 
+    public void testUpdateConnectorRequestWithParsingException() throws Exception {
+        exceptionRule.expect(OpenSearchParseException.class);
+        exceptionRule.expectMessage("Can't get text on a VALUE_NULL");
+        RestRequest request = getRestRequestWithNullValue();
+        restMLUpdateConnectorAction.handleRequest(request, channel, client);
+    }
+
     public void testUpdateConnectorRequestWithEmptyContent() throws Exception {
-        exceptionRule.expect(IOException.class);
+        exceptionRule.expect(OpenSearchParseException.class);
         exceptionRule.expectMessage("Failed to update connector: Request body is empty");
         RestRequest request = getRestRequestWithEmptyContent();
         restMLUpdateConnectorAction.handleRequest(request, channel, client);
@@ -152,6 +159,20 @@ private RestRequest getRestRequest() {
         return request;
     }
 
+    private RestRequest getRestRequestWithNullValue() {
+        RestRequest.Method method = RestRequest.Method.POST;
+        String requestContent = "{\"version\":\"2\",\"description\":null}";
+        Map<String, String> params = new HashMap<>();
+        params.put("connector_id", "test_connectorId");
+        RestRequest request = new FakeRestRequest.Builder(NamedXContentRegistry.EMPTY)
+            .withMethod(method)
+            .withPath("/_plugins/_ml/connectors/_update/{connector_id}")
+            .withParams(params)
+            .withContent(new BytesArray(requestContent), XContentType.JSON)
+            .build();
+        return request;
+    }
+
     private RestRequest getRestRequestWithEmptyContent() {
         RestRequest.Method method = RestRequest.Method.POST;
         Map<String, String> params = new HashMap<>();