diff --git a/src/RibosomeProfiling.nf b/src/RibosomeProfiling.nf
index 82a96198400f63cde3efe78ccda1736677cd5ce3..0f002d4855325a1c7349109caeb7b223cbef474c 100644
--- a/src/RibosomeProfiling.nf
+++ b/src/RibosomeProfiling.nf
@@ -589,7 +589,7 @@ process coverage {
  params.do_postgenome==false
  shell:
  '''
- genome=$(samtools view !{bam[0]} | awk '{print $1} | sort | uniq | wc -l)
+ genome=$(samtools view !{bam[0]} | awk '{print $1}' | sort | uniq | wc -l)
  factor=$(awk -v c=$genome 'BEGIN {print 1000000/c}')
  bamCoverage -p !{task.cpus} --binSize 1 -b !{bam[0]} -o !{file_id}.bigwig
  '''