diff --git a/src/Mutation/Environment/DeployPullRequest.php b/src/Mutation/Environment/DeployPullRequest.php
index 1d72353..b5dcda2 100644
--- a/src/Mutation/Environment/DeployPullRequest.php
+++ b/src/Mutation/Environment/DeployPullRequest.php
@@ -39,6 +39,7 @@ protected function query()
   \$headBranchName: String!
   \$headBranchRef: String!
   \$baseBranchName: String!
+  \$baseBranchRef: String!
 ) {
   deployEnvironmentPullrequest(input: {
     project: {
@@ -48,7 +49,7 @@ protected function query()
     title: \$title
     headBranchName: \$headBranchName
     headBranchRef: \$headBranchRef
-    baseBranchRef: \$baseBranchSha
+    baseBranchRef: \$baseBranchRef
     baseBranchName: \$baseBranchName
   })
 }
diff --git a/tests/Mutation/Environment/DeployPullRequestTest.php b/tests/Mutation/Environment/DeployPullRequestTest.php
index 43901b2..e830609 100644
--- a/tests/Mutation/Environment/DeployPullRequestTest.php
+++ b/tests/Mutation/Environment/DeployPullRequestTest.php
@@ -52,6 +52,7 @@ public function testQuery()
   \$headBranchName: String!
   \$headBranchRef: String!
   \$baseBranchName: String!
+  \$baseBranchRef: String!
 ) {
   deployEnvironmentPullrequest(input: {
     project: {
@@ -61,7 +62,7 @@ public function testQuery()
     title: \$title
     headBranchName: \$headBranchName
     headBranchRef: \$headBranchRef
-    baseBranchRef: \$baseBranchSha
+    baseBranchRef: \$baseBranchRef
     baseBranchName: \$baseBranchName
   })
 }