diff --git a/software/bcftools/merge/main.nf b/software/bcftools/merge/main.nf
index e345c475..3e3238cf 100644
--- a/software/bcftools/merge/main.nf
+++ b/software/bcftools/merge/main.nf
@@ -28,7 +28,7 @@ process BCFTOOLS_MERGE {
     def software = getSoftwareName(task.process)
     prefix       = options.suffix ? "${meta.id}${options.suffix}" : "${meta.id}"
     """
-    bcftools merge -Oz\\
+    bcftools merge -Oz \\
         --output ${prefix}.vcf.gz \\
         $options.args \\
         *.vcf.gz