diff --git a/workflow/main.nf b/workflow/main.nf
index 2fd8fd6bd8cb634f48f6c704fa7187ddfc83ab04..51c5e795f071c3622a74bf3b47db42d1a9dccc5f 100644
--- a/workflow/main.nf
+++ b/workflow/main.nf
@@ -499,8 +499,8 @@ process softwareReport {
   file callPeaksMACS_vf from callPeaksMACSVersions.collect()
   file consensusPeaks_vf from consensusPeaksVersions.collect()
   file peakAnnotation_vf from peakAnnotationVersions.collect()
-  file motifSearch_vf from motifSearchVersions.collect()
-  file diffPeaks_vf from diffPeaksVersions.collect()
+  file motifSearch_vf from motifSearchVersions.collect().ifEmpty([])
+  file diffPeaks_vf from diffPeaksVersions.collect().ifEmpty([])
   file experimentQC_vf from experimentQCVersions.collect()
 
   output: