diff --git a/src/nf_modules/flexi_splitter/main.nf b/src/nf_modules/flexi_splitter/main.nf
index 503699cc6ed5d2df5c709adb0c1d8503705350c1..50e41ac3c55e237496e860afa68829a4bf1e9f77 100644
--- a/src/nf_modules/flexi_splitter/main.nf
+++ b/src/nf_modules/flexi_splitter/main.nf
@@ -22,7 +22,7 @@ process split_fastq {
   // src/nf_modules/flexi_splitter/marseq_flexi_splitter.yaml
   container = "${container_url}"
   label "big_mem_mono_cpus"
-  tag "$file_prefix"
+  tag "$file_id"
   if (params.split_out != "") {
     publishDir "results/${params.split_out}", mode: 'copy'
   }