diff --git a/gridss.wdl b/gridss.wdl
index 03193cca1dfa068a9824035037ce6da7cf66369a..b36d6598a2b1d4f2d8b00ee9cc5ac310f171ba86 100644
--- a/gridss.wdl
+++ b/gridss.wdl
@@ -207,6 +207,7 @@ task Virusbreakend {
         File bam
         File bamIndex
         File referenceFasta
+        File referenceImg
         File virusbreakendDB
         String outputPath = "./virusbreakend.vcf"
 
@@ -246,6 +247,7 @@ task Virusbreakend {
         bam: {description: "A BAM file.", category: "required"}
         bamIndex: {description: "The index for the BAM file.", category: "required"}
         referenceFasta: {description: "The fasta of the reference genome.", category: "required"}
+        referenceImg: {description: "The BWA index image (generated with GATK BwaMemIndexImageCreator) of the reference.", category: "required"}
         virusbreakendDB: {description: "A .tar.gz containing the virusbreakend database.", category: "required"}
         outputPath: {description: "The path the output should be written to.", category: "common"}
         memory: {description: "The amount of memory this job will use.", category: "advanced"}