diff --git a/src/nf_modules/ucsc/main.nf b/src/nf_modules/ucsc/main.nf
index 28967df579eca6f604506eaba9ebaef9d3b792b5..7eccd022c66376344c18543734b324925595043e 100644
--- a/src/nf_modules/ucsc/main.nf
+++ b/src/nf_modules/ucsc/main.nf
@@ -52,7 +52,7 @@ process bigwig_to_wig {
 bigWigToBedGraph ${params.bigwig_to_wig} \
   ${bg} \
   ${bg.simpleName}.bg
-awk '{if(NR>1) {if($1!=lastChrom){printf("variableStep chrom=%s\n",$1);lastChrom=$1;}print $2,$4}}' ${bg.simpleName}.bg > ${bg.simpleName}.wig
+awk '{if(NR>1) {if(\$1!=lastChrom){printf("variableStep chrom=%s\\n",\$1);lastChrom=\$1;}print \$2,\$4}}' ${bg.simpleName}.bg > ${bg.simpleName}.wig
 """
 }