diff --git a/hapi-fhir-docs/src/main/resources/ca/uhn/hapi/fhir/changelog/6_2_0/3980-default-regression-bulk-job.yaml b/hapi-fhir-docs/src/main/resources/ca/uhn/hapi/fhir/changelog/6_2_0/3980-default-regression-bulk-job.yaml
new file mode 100644
index 00000000000..2f81a0a2186
--- /dev/null
+++ b/hapi-fhir-docs/src/main/resources/ca/uhn/hapi/fhir/changelog/6_2_0/3980-default-regression-bulk-job.yaml
@@ -0,0 +1,6 @@
+---
+type: fix
+issue: 3980
+jira: SMILE-5053
+title: "A regression was introduced in 6.1.0 which caused bulk export jobs to not default to the correct output format when the `_outputFormat` parameter was omitted. 
+This behaviour has been fixed, and if omitted, will now default to the only legal value `application/fhir+ndjson`."
diff --git a/hapi-fhir-jpaserver-test-r4/src/test/java/ca/uhn/fhir/jpa/bulk/BulkDataExportProviderTest.java b/hapi-fhir-jpaserver-test-r4/src/test/java/ca/uhn/fhir/jpa/bulk/BulkDataExportProviderTest.java
index 7f39e0634d8..0cb75c6401f 100644
--- a/hapi-fhir-jpaserver-test-r4/src/test/java/ca/uhn/fhir/jpa/bulk/BulkDataExportProviderTest.java
+++ b/hapi-fhir-jpaserver-test-r4/src/test/java/ca/uhn/fhir/jpa/bulk/BulkDataExportProviderTest.java
@@ -175,6 +175,28 @@ public class BulkDataExportProviderTest {
 		assertTrue(params.getFilters().contains(filter));
 	}
 
+	@Test
+	public void testOmittingOutputFormatDefaultsToNdjson() throws IOException {
+		when(myJobRunner.startNewJob(any()))
+			.thenReturn(createJobStartResponse());
+
+		InstantType now = InstantType.now();
+
+		Parameters input = new Parameters();
+		HttpPost post = new HttpPost("http://localhost:" + myPort + "/" + JpaConstants.OPERATION_EXPORT);
+		post.addHeader(Constants.HEADER_PREFER, Constants.HEADER_PREFER_RESPOND_ASYNC);
+		post.setEntity(new ResourceEntity(myCtx, input));
+
+		try (CloseableHttpResponse response = myClient.execute(post)) {
+			assertEquals(202, response.getStatusLine().getStatusCode());
+		}
+
+		BulkExportParameters params = verifyJobStart();
+		assertEquals(Constants.CT_FHIR_NDJSON, params.getOutputFormat());
+
+
+	}
+
 	@Test
 	public void testSuccessfulInitiateBulkRequest_Get() throws IOException {
 		when(myJobRunner.startNewJob(any())).thenReturn(createJobStartResponse());
diff --git a/hapi-fhir-storage/src/main/java/ca/uhn/fhir/jpa/bulk/export/provider/BulkDataExportProvider.java b/hapi-fhir-storage/src/main/java/ca/uhn/fhir/jpa/bulk/export/provider/BulkDataExportProvider.java
index 7e866e77f80..11240da0682 100644
--- a/hapi-fhir-storage/src/main/java/ca/uhn/fhir/jpa/bulk/export/provider/BulkDataExportProvider.java
+++ b/hapi-fhir-storage/src/main/java/ca/uhn/fhir/jpa/bulk/export/provider/BulkDataExportProvider.java
@@ -365,7 +365,7 @@ public class BulkDataExportProvider {
 	}
 
 	private BulkDataExportOptions buildBulkDataExportOptions(IPrimitiveType<String> theOutputFormat, IPrimitiveType<String> theType, IPrimitiveType<Date> theSince, List<IPrimitiveType<String>> theTypeFilter, BulkDataExportOptions.ExportStyle theExportStyle) {
-		String outputFormat = theOutputFormat != null ? theOutputFormat.getValueAsString() : null;
+		String outputFormat = theOutputFormat != null ? theOutputFormat.getValueAsString() : Constants.CT_FHIR_NDJSON;
 
 		Set<String> resourceTypes = null;
 		if (theType != null) {