diff --git a/api/project.go b/api/project.go
index 7fd261c..dece372 100644
--- a/api/project.go
+++ b/api/project.go
@@ -98,8 +98,10 @@ func Project(g *gin.RouterGroup, db database.Database) {
 
 		project.Update(update)
 
-		if project.StartTime != nil && (project.EndTime == nil || !project.StartTime.Before(*project.EndTime)) {
+		if project.EndTime != nil && project.StartTime != nil && (project.EndTime == nil || !project.StartTime.Before(*project.EndTime)) {
 			return nil, slerrors.BadRequest("Project start time must be before end time.")
+		} else {
+			project.StartTime = nil
 		}
 
 		err = db.Projects().Update(c.Request.Context(), project.Project)