diff --git a/crates/fayalite/src/cli.rs b/crates/fayalite/src/cli.rs
index a236c77..1030474 100644
--- a/crates/fayalite/src/cli.rs
+++ b/crates/fayalite/src/cli.rs
@@ -610,6 +610,7 @@ impl FormalArgs {
         });
         std::fs::write(&sby_file, sby_contents)?;
         let mut cmd = process::Command::new(&self.sby);
+        cmd.arg("-j1"); // sby seems not to respect job count in parallel mode
         cmd.arg("-f");
         cmd.arg(sby_file.file_name().unwrap());
         cmd.args(&self.sby_extra_args);