diff --git a/README.md b/README.md
index c2da6e6c..7fbc5820 100644
--- a/README.md
+++ b/README.md
@@ -714,6 +714,7 @@ GITLAB_OA_LAST_COMMIT_AUTHOR_EMAIL
 GITLAB_OA_WIP
 GITLAB_OA_URL
 GITLAB_OA_ACTION
+GITLAB_OA_OLDREV
 GITLAB_OA_ASSIGNEE_NAME
 GITLAB_OA_ASSIGNEE_USERNAME
 GITLAB_OA_ASSIGNEE_AVATAR_URL
diff --git a/src/main/java/io/jenkins/plugins/gitlabbranchsource/Cause/GitLabMergeRequestCauseData.java b/src/main/java/io/jenkins/plugins/gitlabbranchsource/Cause/GitLabMergeRequestCauseData.java
index 848769bc..4c4018cd 100644
--- a/src/main/java/io/jenkins/plugins/gitlabbranchsource/Cause/GitLabMergeRequestCauseData.java
+++ b/src/main/java/io/jenkins/plugins/gitlabbranchsource/Cause/GitLabMergeRequestCauseData.java
@@ -295,6 +295,9 @@ public GitLabMergeRequestCauseData(MergeRequestEvent mergeRequestEvent) {
         this.variables.put(
                 "GITLAB_OA_ACTION",
                 defaultString(mergeRequestEvent.getObjectAttributes().getAction()));
+        this.variables.put(
+                "GITLAB_OA_OLDREV",
+                defaultString(mergeRequestEvent.getObjectAttributes().getOldrev()));
         if (mergeRequestEvent.getObjectAttributes().getAssignee() != null) {
             this.variables.put(
                     "GITLAB_OA_ASSIGNEE_NAME",