diff --git a/ofborg/src/bin/builder.rs b/ofborg/src/bin/builder.rs
index 59e1797..18b1308 100644
--- a/ofborg/src/bin/builder.rs
+++ b/ofborg/src/bin/builder.rs
@@ -60,7 +60,9 @@ struct BuildWorker {
 }
 
 impl worker::SimpleWorker for BuildWorker {
-    fn consumer<BuildJob>(&self, job: BuildJob, resp: Actions) -> Result<(), Error> {
+    type J = BuildJob;
+
+    fn consumer(&self, job: BuildJob, resp: Actions) -> Result<(), Error> {
         let project = self.cloner.project(job.repo.full_name, job.repo.clone_url);
         let co = project.clone_for("builder".to_string(),
                                    job.pr.number.to_string())?;
diff --git a/ofborg/src/worker.rs b/ofborg/src/worker.rs
index f3586c8..d7ce25d 100644
--- a/ofborg/src/worker.rs
+++ b/ofborg/src/worker.rs
@@ -23,7 +23,8 @@ pub struct Actions {
 }
 
 pub trait SimpleWorker {
-    fn consumer<J>(&self, job: J, resp: Actions) -> Result<(), Error>;
+    type J;
+    fn consumer(&self, job: Self::J, resp: Actions) -> Result<(), Error>;
 }
 
 pub fn new<T: SimpleWorker>(worker: T) -> Worker<T> {