diff --git a/playbooks/groups/jenkins-cloud.yml b/playbooks/groups/jenkins-cloud.yml
index ea3b1450d0..f9259d5d1d 100644
--- a/playbooks/groups/jenkins-cloud.yml
+++ b/playbooks/groups/jenkins-cloud.yml
@@ -136,7 +136,7 @@
           version: 2.2
           sha: b373d99ffbdec45375fcf00be329d7b5029ab195f5b48d2d7518c776ed4bf1b8
         - name: mercurial
-          version: 1.50
+          version: '1.50'
           sha: 934a6bd38e2109b97c915d80fdb6abc74a8ef4aff882b94ef0b1a274919ea407
         - name: openid
           version: 1.8