diff --git a/fastqc.wdl b/fastqc.wdl
index e526c1e9432df7c924ac4aaf063867c242c58cf3..968c4a49ffb2dee7b4025d533856080d76585f09 100644
--- a/fastqc.wdl
+++ b/fastqc.wdl
@@ -70,7 +70,7 @@ task extractAdapters {
     command {
     set -e
     mkdir -p ${outputDir}
-    java -Xmx$${true=""+memory false="4" defined(memory)}G -jar ${extractAdaptersFastqcJar} \
+    java -Xmx${true=""+memory false="4" defined(memory)}G -jar ${extractAdaptersFastqcJar} \
     --inputFile ${inputFile} \
     ${"--adapterOutputFile " + adapterOutputFilePath } \
     ${"--contamsOutputFile " + contamsOutputFilePath } \