diff --git a/workflow/rules/ref.smk b/workflow/rules/ref.smk
index 9be480ba..685c49b2 100644
--- a/workflow/rules/ref.smk
+++ b/workflow/rules/ref.smk
@@ -63,7 +63,7 @@ rule star_index:
         directory("resources/star_genome"),
     threads: 4
     params:
-        extra="--sjdbGTFfile resources/genome.gtf --sjdbOverhang 100",
+        extra=lambda wc, input: f"--sjdbGTFfile {input.annotation} --sjdbOverhang 100",
     log:
         "logs/star_index_genome.log",
     cache: True