diff --git a/public/flexiprep/src/main/scala/nl/lumc/sasc/biopet/pipelines/flexiprep/Flexiprep.scala b/public/flexiprep/src/main/scala/nl/lumc/sasc/biopet/pipelines/flexiprep/Flexiprep.scala
index 660ddbd88f7eb4c3ffa42f23140abc3487fb61fd..373ac0a93f94f31f4d0370234f4b2c008ecd9777 100644
--- a/public/flexiprep/src/main/scala/nl/lumc/sasc/biopet/pipelines/flexiprep/Flexiprep.scala
+++ b/public/flexiprep/src/main/scala/nl/lumc/sasc/biopet/pipelines/flexiprep/Flexiprep.scala
@@ -221,6 +221,7 @@ class Flexiprep(val root: Configurable) extends QScript with SummaryQScript with
         fqSync.outputFastq1 = swapExt(outDir, R1, R1_ext, ".sync" + R1_ext)
         fqSync.outputFastq2 = swapExt(outDir, R2.get, R2_ext, ".sync" + R2_ext)
         fqSync.outputStats = swapExt(outDir, R1, R1_ext, ".sync.stats")
+        fqSync.isIntermediate = true
         fqSync.deps :::= deps
         add(fqSync)
         addSummarizable(fqSync, "fastq_sync")