diff --git a/biopet.wdl b/biopet.wdl
index 8ac1d975faff8c5f1af8a58536e7a10c8b0b4489..554c75418aab199ad95035e8699ea59566184420 100644
--- a/biopet.wdl
+++ b/biopet.wdl
@@ -65,7 +65,7 @@ task SampleConfig {
         set -e -o pipefail
         ${preCommand}
         mkdir -p . ${"$(dirname " + jsonOutputPath + ")"} ${"$(dirname " + tsvOutputPath + ")"}
-        java -Xmx${default=3 memory}G -jar ${tool_jar} \
+        java -Xmx${default=3.0 memory}G -jar ${tool_jar} \
         -i ${sep="-i " inputFiles} \
         ${"--sample " + sample} \
         ${"--library " + library} \
@@ -101,7 +101,7 @@ task BaseCounter {
         set -e -o pipefail
         ${preCommand}
         mkdir -p ${outputDir}
-        java -Xmx${default=12 memory}G -jar ${tool_jar} \
+        java -Xmx${default=12.0 memory}G -jar ${tool_jar} \
         -b ${bam} \
         -r ${refFlat} \
         -o ${outputDir} \
diff --git a/fastqc.wdl b/fastqc.wdl
index cdda2f0168b2cfbf8daf4333b4aa060108b9a7e5..12b481ebb4ed2818dbadb9d62f6cc40538042841 100644
--- a/fastqc.wdl
+++ b/fastqc.wdl
@@ -69,7 +69,7 @@ task extractAdapters {
     command {
     set -e
     mkdir -p ${outputDir}
-    java -Xmx${default=4 memory}G -jar ${extractAdaptersFastqcJar} \
+    java -Xmx${default=4.0 memory}G -jar ${extractAdaptersFastqcJar} \
     --inputFile ${inputFile} \
     ${"--adapterOutputFile " + adapterOutputFilePath } \
     ${"--contamsOutputFile " + contamsOutputFilePath } \