diff --git a/public/biopet-framework/src/main/scala/nl/lumc/sasc/biopet/core/summary/WriteSummary.scala b/public/biopet-framework/src/main/scala/nl/lumc/sasc/biopet/core/summary/WriteSummary.scala
index 6f98d9573e09686e0709f4b31eea82ff00d4dd8b..75bf66d6671a35541f454b553761d62b83b8181a 100644
--- a/public/biopet-framework/src/main/scala/nl/lumc/sasc/biopet/core/summary/WriteSummary.scala
+++ b/public/biopet-framework/src/main/scala/nl/lumc/sasc/biopet/core/summary/WriteSummary.scala
@@ -53,7 +53,7 @@ class WriteSummary(val root: Configurable) extends InProcessFunction with Config
         (for (f <- qscript.functions if f.isInstanceOf[BiopetCommandLineFunctionTrait]) yield {
           f match {
             case f: BiopetCommandLineFunctionTrait => {
-              f.configName -> Map("version" -> f.getVersion,
+              f.configName -> Map("version" -> f.getVersion.getOrElse(None),
                 "md5" -> BiopetCommandLineFunctionTrait.executableMd5Cache.getOrElse(f.executable, None))
             }
             case _ => throw new IllegalStateException("This should not be possible")