diff --git a/java/src/org/broadinstitute/sting/gatk/io/stubs/VCFWriterStub.java b/java/src/org/broadinstitute/sting/gatk/io/stubs/VCFWriterStub.java
index f9b86665e..1a1981300 100755
--- a/java/src/org/broadinstitute/sting/gatk/io/stubs/VCFWriterStub.java
+++ b/java/src/org/broadinstitute/sting/gatk/io/stubs/VCFWriterStub.java
@@ -199,6 +199,6 @@ public class VCFWriterStub implements Stub<VCFWriter>, VCFWriter {
      */
     private VCFHeaderLine getCommandLineArgumentHeaderLine() {
         CommandLineExecutable executable = JVMUtils.getObjectOfType(argumentSources,CommandLineExecutable.class);
-        return new VCFHeaderLine(executable.getAnalysisName(), "\"" + CommandLineUtils.createApproximateCommandLineArgumentString(argumentSources) + "\"");
+        return new VCFHeaderLine(executable.getAnalysisName(), "\"" + CommandLineUtils.createApproximateCommandLineArgumentString(argumentSources.toArray()) + "\"");
     }
 }
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