diff --git a/modules/genmap/mappability/main.nf b/modules/genmap/mappability/main.nf
index 50a17493..0233a271 100644
--- a/modules/genmap/mappability/main.nf
+++ b/modules/genmap/mappability/main.nf
@@ -1,5 +1,5 @@
 process GENMAP_MAPPABILITY {
-    tag '$fasta'
+    tag '$index'
     label 'process_high'
 
     conda (params.enable_conda ? "bioconda::genmap=1.3.0" : null)