diff --git a/src/nf_modules/bwa/main.nf b/src/nf_modules/bwa/main.nf
index dd5cc3906fc79703cf87498f90d18f3a6d23e38f..d427549c7634d1f51eaef59269715b383c038c0d 100644
--- a/src/nf_modules/bwa/main.nf
+++ b/src/nf_modules/bwa/main.nf
@@ -49,7 +49,7 @@ process mapping_fastq {
   if (file_id instanceof List){
     library = file_id[0]
     file_prefix = file_id[0]
-  else if (file_id.containsKey('library')) {
+  } else if (file_id.containsKey('library')) {
     library = file_id.library
     file_prefix = file_id.id
   } else {