diff --git a/tasks/utilities/file_handling/task_cat_lanes.wdl b/tasks/utilities/file_handling/task_cat_lanes.wdl
index 60a2b7d28..8efb2c363 100644
--- a/tasks/utilities/file_handling/task_cat_lanes.wdl
+++ b/tasks/utilities/file_handling/task_cat_lanes.wdl
@@ -32,7 +32,7 @@ task cat_lanes {
 
     cat ~{read1_lane1} ~{read1_lane2} ~{read1_lane3} ~{read1_lane4} > "~{samplename}_merged_R1.fastq.gz"
 
-    if exists ~{read2_lane1} ; then
+    if exists "~{read2_lane1}" ; then
       cat ~{read2_lane1} ~{read2_lane2} ~{read2_lane3} ~{read2_lane4} > "~{samplename}_merged_R2.fastq.gz"
     fi