diff --git a/hapi-fhir-base/src/main/java/ca/uhn/fhir/parser/JsonParser.java b/hapi-fhir-base/src/main/java/ca/uhn/fhir/parser/JsonParser.java
index 10b8609356a..4dea1260aca 100644
--- a/hapi-fhir-base/src/main/java/ca/uhn/fhir/parser/JsonParser.java
+++ b/hapi-fhir-base/src/main/java/ca/uhn/fhir/parser/JsonParser.java
@@ -317,19 +317,14 @@ public class JsonParser extends BaseParser implements IJsonLikeParser {
 			}
 			case CONTAINED_RESOURCE_LIST:
 			case CONTAINED_RESOURCES: {
-				/*
-				 * Disabled per #103 ContainedDt value = (ContainedDt) theNextValue; for (IResource next :
-				 * value.getContainedResources()) { if (getContainedResources().getResourceId(next) != null) { continue; }
-				 * encodeResourceToJsonStreamWriter(theResDef, next, theWriter, null, true,
-				 * fixContainedResourceId(next.getId().getValue())); }
-				 */
 				List<IBaseResource> containedResources = getContainedResources().getContainedResources();
 				if (containedResources.size() > 0) {
 					beginArray(theEventWriter, theChildName);
 
 					for (IBaseResource next : containedResources) {
 						IIdType resourceId = getContainedResources().getResourceId(next);
-						encodeResourceToJsonStreamWriter(theResDef, next, theEventWriter, null, true, fixContainedResourceId(resourceId.getValue()), theEncodeContext);
+						String value = resourceId.getValue();
+						encodeResourceToJsonStreamWriter(theResDef, next, theEventWriter, null, true, fixContainedResourceId(value), theEncodeContext);
 					}
 
 					theEventWriter.endArray();
@@ -359,7 +354,7 @@ public class JsonParser extends BaseParser implements IJsonLikeParser {
 				RuntimeResourceDefinition def = myContext.getResourceDefinition(resource);
 
 				theEncodeContext.pushPath(def.getName(), true);
-				encodeResourceToJsonStreamWriter(def, resource, theEventWriter, theChildName, false, theEncodeContext);
+				encodeResourceToJsonStreamWriter(def, resource, theEventWriter, theChildName, theContainedResource, theEncodeContext);
 				theEncodeContext.popPath();
 
 				break;
diff --git a/hapi-fhir-base/src/main/java/ca/uhn/fhir/parser/XmlParser.java b/hapi-fhir-base/src/main/java/ca/uhn/fhir/parser/XmlParser.java
index 2ed7221cc16..a09ad1208be 100644
--- a/hapi-fhir-base/src/main/java/ca/uhn/fhir/parser/XmlParser.java
+++ b/hapi-fhir-base/src/main/java/ca/uhn/fhir/parser/XmlParser.java
@@ -287,7 +287,8 @@ public class XmlParser extends BaseParser {
 					for (IBaseResource next : getContainedResources().getContainedResources()) {
 						IIdType resourceId = getContainedResources().getResourceId(next);
 						theEventWriter.writeStartElement("contained");
-						encodeResourceToXmlStreamWriter(next, theEventWriter, true, fixContainedResourceId(resourceId.getValue()), theEncodeContext);
+						String value = resourceId.getValue();
+						encodeResourceToXmlStreamWriter(next, theEventWriter, true, fixContainedResourceId(value), theEncodeContext);
 						theEventWriter.writeEndElement();
 					}
 					break;
@@ -300,7 +301,7 @@ public class XmlParser extends BaseParser {
 					}
 					theEventWriter.writeStartElement(theChildName);
 					theEncodeContext.pushPath(resourceName, true);
-					encodeResourceToXmlStreamWriter(resource, theEventWriter, false, theEncodeContext);
+					encodeResourceToXmlStreamWriter(resource, theEventWriter, theIncludedResource, theEncodeContext);
 					theEncodeContext.popPath();
 					theEventWriter.writeEndElement();
 					break;
diff --git a/hapi-fhir-docs/src/main/resources/ca/uhn/hapi/fhir/changelog/4_3_0/1778-avoid-crash-encoding-contained-bundle.yaml b/hapi-fhir-docs/src/main/resources/ca/uhn/hapi/fhir/changelog/4_3_0/1778-avoid-crash-encoding-contained-bundle.yaml
new file mode 100644
index 00000000000..d7c698890e9
--- /dev/null
+++ b/hapi-fhir-docs/src/main/resources/ca/uhn/hapi/fhir/changelog/4_3_0/1778-avoid-crash-encoding-contained-bundle.yaml
@@ -0,0 +1,5 @@
+---
+type: fix
+issue: 1778
+title: "When encoding a resource, a crash could occur if the resource had a contained Bundle resource. This
+  is not commonly done, but there are valid scenarios for doing so."
diff --git a/hapi-fhir-structures-r4/src/test/java/ca/uhn/fhir/parser/JsonParserR4Test.java b/hapi-fhir-structures-r4/src/test/java/ca/uhn/fhir/parser/JsonParserR4Test.java
index 3b30dfb70b9..350746625aa 100644
--- a/hapi-fhir-structures-r4/src/test/java/ca/uhn/fhir/parser/JsonParserR4Test.java
+++ b/hapi-fhir-structures-r4/src/test/java/ca/uhn/fhir/parser/JsonParserR4Test.java
@@ -789,6 +789,40 @@ public class JsonParserR4Test extends BaseTest {
 		return b;
 	}
 
+	/**
+	 * Ensure that a contained bundle doesn't cause a crash
+	 */
+	@Test
+	public void testEncodeContainedBundle() {
+		String auditEvent = "{\n" +
+			"  \"resourceType\": \"AuditEvent\",\n" +
+			"  \"contained\": [ {\n" +
+			"    \"resourceType\": \"Bundle\",\n" +
+			"    \"id\": \"REASONS\",\n" +
+			"    \"entry\": [ {\n" +
+			"      \"resource\": {\n" +
+			"        \"resourceType\": \"Condition\",\n" +
+			"        \"id\": \"123\"\n" +
+			"      }\n" +
+			"    } ]\n" +
+			"  }, {\n" +
+			"    \"resourceType\": \"MeasureReport\",\n" +
+			"    \"id\": \"MRPT5000602611RD\",\n" +
+			"    \"evaluatedResource\": [ {\n" +
+			"      \"reference\": \"#REASONS\"\n" +
+			"    } ]\n" +
+			"  } ],\n" +
+			"  \"entity\": [ {\n" +
+			"    \"what\": {\n" +
+			"      \"reference\": \"#MRPT5000602611RD\"\n" +
+			"    }\n" +
+			"  } ]\n" +
+			"}";
+		AuditEvent ae = ourCtx.newJsonParser().parseResource(AuditEvent.class, auditEvent);
+		String auditEventAsString = ourCtx.newJsonParser().setPrettyPrint(true).encodeResourceToString(ae);
+		assertEquals(auditEvent, auditEventAsString);
+	}
+
 
 	@AfterClass
 	public static void afterClassClearContext() {
diff --git a/hapi-fhir-structures-r4/src/test/java/ca/uhn/fhir/parser/XmlParserR4Test.java b/hapi-fhir-structures-r4/src/test/java/ca/uhn/fhir/parser/XmlParserR4Test.java
index e109aa84490..536dce99b7e 100644
--- a/hapi-fhir-structures-r4/src/test/java/ca/uhn/fhir/parser/XmlParserR4Test.java
+++ b/hapi-fhir-structures-r4/src/test/java/ca/uhn/fhir/parser/XmlParserR4Test.java
@@ -9,6 +9,7 @@ import static org.junit.Assert.assertThat;
 import ca.uhn.fhir.test.BaseTest;
 
 import org.hl7.fhir.instance.model.api.IBaseResource;
+import org.hl7.fhir.r4.model.AuditEvent;
 import org.hl7.fhir.r4.model.Bundle;
 import org.hl7.fhir.r4.model.Composition;
 import org.hl7.fhir.r4.model.DocumentReference;
@@ -115,5 +116,43 @@ public class XmlParserR4Test extends BaseTest {
 		ourLog.info(encoded);
 	}
 
+	/**
+	 * Ensure that a contained bundle doesn't cause a crash
+	 */
+	@Test
+	public void testEncodeContainedBundle() {
+		String auditEvent = "<AuditEvent xmlns=\"http://hl7.org/fhir\">\n" +
+			"   <contained>\n" +
+			"      <Bundle xmlns=\"http://hl7.org/fhir\">\n" +
+			"         <id value=\"REASONS\"/>\n" +
+			"         <entry>\n" +
+			"            <resource>\n" +
+			"               <Condition xmlns=\"http://hl7.org/fhir\">\n" +
+			"                  <id value=\"123\"/>\n" +
+			"               </Condition>\n" +
+			"            </resource>\n" +
+			"         </entry>\n" +
+			"      </Bundle>\n" +
+			"   </contained>\n" +
+			"   <contained>\n" +
+			"      <MeasureReport xmlns=\"http://hl7.org/fhir\">\n" +
+			"         <id value=\"MRPT5000602611RD\"/>\n" +
+			"         <evaluatedResource>\n" +
+			"            <reference value=\"#REASONS\"/>\n" +
+			"         </evaluatedResource>\n" +
+			"      </MeasureReport>\n" +
+			"   </contained>\n" +
+			"   <entity>\n" +
+			"      <what>\n" +
+			"         <reference value=\"#MRPT5000602611RD\"/>\n" +
+			"      </what>\n" +
+			"   </entity>\n" +
+			"</AuditEvent>";
+		AuditEvent ae = ourCtx.newXmlParser().parseResource(AuditEvent.class, auditEvent);
+		String auditEventAsString = ourCtx.newXmlParser().setPrettyPrint(true).encodeResourceToString(ae);
+		assertEquals(auditEvent, auditEventAsString);
+	}
+
+
 
 }