diff --git a/src/com/mirantis/mcp/MCPArtifactory.groovy b/src/com/mirantis/mcp/MCPArtifactory.groovy
index ffce300..0b06a5e 100644
--- a/src/com/mirantis/mcp/MCPArtifactory.groovy
+++ b/src/com/mirantis/mcp/MCPArtifactory.groovy
@@ -257,7 +257,7 @@
                           String artifactoryProdRepo, String dockerRepo,
                           String artifactTag, String targetTag, Boolean copy = false) {
     def url = "${artifactoryURL}/api/docker/${artifactoryDevRepo}/v2/promote"
-    String queryFile = UUID.randomUUID()
+    String queryFile = UUID.randomUUID().toString()
     writeFile file: queryFile,
             text: """{
                   \"targetRepo\": \"${artifactoryProdRepo}\",