diff --git a/src/nf_modules/bowtie2/main.nf b/src/nf_modules/bowtie2/main.nf
index efd0ceb358cce419572e3a2a33a50713a32ad912..1dc0780d52dc6b5118022a91fdf2b5c9c9f73e59 100644
--- a/src/nf_modules/bowtie2/main.nf
+++ b/src/nf_modules/bowtie2/main.nf
@@ -46,7 +46,7 @@ process mapping_fastq {
   tuple val(file_id), path(reads)
 
   output:
-  tuple val(), path("*.bam"), emit: bam
+  tuple val(file_id), path("*.bam"), emit: bam
   path "*_report.txt", emit: report
 
   script: