diff --git a/.drone.yml b/.drone.yml
index a47bf0e..2db6aad 100644
--- a/.drone.yml
+++ b/.drone.yml
@@ -25,7 +25,7 @@ pipeline:
     image: plugins/docker:17.05
     pull: true
     repo: plugins/git
-    tags: [ latest, 1.4.0, 1.4, 1 ]
+    tags: [ latest, 1.3.0, 1.3, 1 ]
     secrets: [ docker_username, docker_password ]
     dockerfile: Dockerfile
     when:
diff --git a/plugin.go b/plugin.go
index 52ac356..593f551 100644
--- a/plugin.go
+++ b/plugin.go
@@ -38,12 +38,12 @@ func (p Plugin) Exec() error {
 		cmds = append(cmds, remote(p.Repo.Clone))
 	}
 
-	cmds = append(cmds, fetch(p.Build.Ref, p.Config.Tags, p.Config.Depth))
-
 	switch {
-	case isTag(p.Build.Event, p.Build.Ref):
+	case isPullRequest(p.Build.Event) || isTag(p.Build.Event, p.Build.Ref):
+		cmds = append(cmds, fetch(p.Build.Ref, p.Config.Tags, p.Config.Depth))
 		cmds = append(cmds, checkoutHead())
 	default:
+		cmds = append(cmds, fetch(p.Build.Ref, p.Config.Tags, p.Config.Depth))
 		cmds = append(cmds, checkoutSha(p.Build.Commit))
 	}
 
diff --git a/plugin_test.go b/plugin_test.go
index 046652e..1cbe40d 100644
--- a/plugin_test.go
+++ b/plugin_test.go
@@ -48,7 +48,7 @@ var commits = []struct {
 		clone:  "https://github.com/octocat/Hello-World.git",
 		event:  "pull_request",
 		branch: "master",
-		commit: "43617d6cc59d91c7d99909042c19ff122e2597fb",
+		commit: "553c2077f0edc3d5dc5d17262f6aa498e69d6f8e",
 		ref:    "refs/pull/208/merge",
 		file:   "README",
 		data:   "Goodbye World!\n",
diff --git a/utils.go b/utils.go
index 85b960d..896c551 100644
--- a/utils.go
+++ b/utils.go
@@ -29,6 +29,11 @@ func isDirEmpty(dir string) bool {
 	return err == io.EOF
 }
 
+// helper function returns true if the commit is a pull_request.
+func isPullRequest(event string) bool {
+	return event == "pull_request"
+}
+
 // helper function returns true if the commit is a tag.
 func isTag(event, ref string) bool {
 	return event == "tag" ||