diff --git a/apps/dhp-mdstore-manager/src/main/java/eu/dnetlib/data/mdstore/manager/controller/MDStoreController.java b/apps/dhp-mdstore-manager/src/main/java/eu/dnetlib/data/mdstore/manager/controller/MDStoreController.java
index b17e9e81..185e3b34 100644
--- a/apps/dhp-mdstore-manager/src/main/java/eu/dnetlib/data/mdstore/manager/controller/MDStoreController.java
+++ b/apps/dhp-mdstore-manager/src/main/java/eu/dnetlib/data/mdstore/manager/controller/MDStoreController.java
@@ -152,20 +152,21 @@ public class MDStoreController extends AbstractDnetController {
 	@ApiOperation("Delete expired versions")
 	@DeleteMapping("/versions/expired")
 	public StatusResponse deleteExpiredVersions() {
-		new Thread(() -> {
-			for (final String versionId : databaseUtils.listExpiredVersions()) {
-				try {
-					final String hdfsPath = databaseUtils.deleteMdStoreVersion(versionId, true);
-					hdfsClient.deletePath(hdfsPath);
-				} catch (final MDStoreManagerException e) {
-					log.warn("Error deleteting version " + versionId, e);
-				}
-			}
-		}).start();
-
+		new Thread(this::performDeleteOfExpiredVersions).start();
 		return StatusResponse.DELETING;
 	}
 
+	private synchronized void performDeleteOfExpiredVersions() {
+		for (final String versionId : databaseUtils.listExpiredVersions()) {
+			try {
+				final String hdfsPath = databaseUtils.deleteMdStoreVersion(versionId, true);
+				hdfsClient.deletePath(hdfsPath);
+			} catch (final MDStoreManagerException e) {
+				log.warn("Error deleteting version " + versionId, e);
+			}
+		}
+	}
+
 	@ApiOperation("Fix the inconsistencies on HDFS")
 	@GetMapping("/hdfs/inconsistencies")
 	public Set<String> fixHdfsInconsistencies(