diff --git a/cg/meta/workflow/raredisease.py b/cg/meta/workflow/raredisease.py
index 4cee2a7a02..a7e940c0f1 100644
--- a/cg/meta/workflow/raredisease.py
+++ b/cg/meta/workflow/raredisease.py
@@ -271,3 +271,7 @@ def get_sample_coverage(
     def get_scout_upload_case_tags(self) -> dict:
         """Return Raredisease Scout upload case tags."""
         return RAREDISEASE_CASE_TAGS
+
+    def get_genome_build(self, case_id: str) -> GenomeVersion:
+        """Return reference genome for a raredisease case. Currently fixed for hg19."""
+        return GenomeVersion.HG19