diff --git a/api/build.go b/api/build.go
index c508d2bef..075a80c36 100644
--- a/api/build.go
+++ b/api/build.go
@@ -990,6 +990,15 @@ func RestartBuild(c *gin.Context) {
 	b.SetRuntime("")
 	b.SetDistribution("")
 
+	// update the PR event action if action was never set
+	// for backwards compatibility with pre-0.14 releases.
+	if b.GetEvent() == constants.EventPull && b.GetEventAction() == "" {
+		// technically, the action could have been opened or synchronize.
+		// will not affect behavior of the pipeline since we did not
+		// support actions for builds where this would be the case.
+		b.SetEventAction(constants.ActionOpened)
+	}
+
 	// set the parent equal to the restarted build number
 	b.SetParent(b.GetNumber())
 	// update the build numbers based off repo counter