diff --git a/.github/workflows/pr-title-validate.yml b/.github/workflows/pr-title-validate.yml
index f62dacf0..aa3588f6 100644
--- a/.github/workflows/pr-title-validate.yml
+++ b/.github/workflows/pr-title-validate.yml
@@ -12,6 +12,6 @@ jobs:
     runs-on: ubuntu-latest
     
     steps:
-    - name: validate
+    - name: validate title
       run: |
         echo "${{ github.event.pull_request.title }}" | grep -Eq '^(feat|fix|chore|refactor|enhance|test|docs)\(.*\):.*$' && (echo "Pass"; exit 0) || (echo "Incorrect Format. Please see https://go-vela.github.io/docs/community/contributing_guidelines/#development-workflow"; exit 1)
\ No newline at end of file
diff --git a/library/build.go b/library/build.go
index 5b919dfb..3c872933 100644
--- a/library/build.go
+++ b/library/build.go
@@ -148,6 +148,8 @@ func (b *Build) Environment(workspace, channel string) map[string]string {
 		envs["BUILD_PULL_REQUEST_NUMBER"] = number
 		envs["VELA_BUILD_PULL_REQUEST"] = number
 		envs["VELA_PULL_REQUEST"] = number
+		envs["VELA_PULL_REQUEST_SOURCE"] = b.GetHeadRef()
+		envs["VELA_PULL_REQUEST_TARGET"] = b.GetBaseRef()
 	}
 
 	// check if the Build event is deployment
diff --git a/library/build_test.go b/library/build_test.go
index bd0b265c..5c82c7a3 100644
--- a/library/build_test.go
+++ b/library/build_test.go
@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"github.com/go-vela/types/raw"
+	"github.com/google/go-cmp/cmp"
 )
 
 func TestLibrary_Build_Duration(t *testing.T) {
@@ -51,6 +52,8 @@ func TestLibrary_Build_Environment(t *testing.T) {
 	_comment.SetEvent("comment")
 	_comment.SetEventAction("created")
 	_comment.SetRef("refs/pulls/1/head")
+	_comment.SetHeadRef("dev")
+	_comment.SetBaseRef("main")
 
 	_deploy := testBuild()
 	_deploy.SetEvent("deployment")
@@ -146,7 +149,7 @@ func TestLibrary_Build_Environment(t *testing.T) {
 				"VELA_BUILD_APPROVED_BY":    "OctoCat",
 				"VELA_BUILD_AUTHOR":         "OctoKitty",
 				"VELA_BUILD_AUTHOR_EMAIL":   "OctoKitty@github.com",
-				"VELA_BUILD_BASE_REF":       "",
+				"VELA_BUILD_BASE_REF":       "main",
 				"VELA_BUILD_BRANCH":         "main",
 				"VELA_BUILD_CHANNEL":        "TODO",
 				"VELA_BUILD_CLONE":          "https://github.com/github/octocat.git",
@@ -171,9 +174,11 @@ func TestLibrary_Build_Environment(t *testing.T) {
 				"VELA_BUILD_TITLE":          "push received from https://github.com/github/octocat",
 				"VELA_BUILD_WORKSPACE":      "TODO",
 				"VELA_PULL_REQUEST":         "1",
+				"VELA_PULL_REQUEST_SOURCE":  "dev",
+				"VELA_PULL_REQUEST_TARGET":  "main",
 				"BUILD_AUTHOR":              "OctoKitty",
 				"BUILD_AUTHOR_EMAIL":        "OctoKitty@github.com",
-				"BUILD_BASE_REF":            "",
+				"BUILD_BASE_REF":            "main",
 				"BUILD_BRANCH":              "main",
 				"BUILD_CHANNEL":             "TODO",
 				"BUILD_CLONE":               "https://github.com/github/octocat.git",
@@ -439,8 +444,8 @@ func TestLibrary_Build_Environment(t *testing.T) {
 	for _, test := range tests {
 		got := test.build.Environment("TODO", "TODO")
 
-		if !reflect.DeepEqual(got, test.want) {
-			t.Errorf("Environment is %v, want %v", got, test.want)
+		if diff := cmp.Diff(test.want, got); diff != "" {
+			t.Errorf("(Environment: -want +got):\n%s", diff)
 		}
 	}
 }