diff --git a/biowdl.wdl b/biowdl.wdl
index 7392983ad23c33c8de3d7cd9afce67a31a255146..fe49a6cf770c0a257aa0d9bf2ad5442a73a7fc1d 100644
--- a/biowdl.wdl
+++ b/biowdl.wdl
@@ -86,7 +86,7 @@ task IndexFastaFile {
     command <<<
         set -e
         mkdir -p ~{outputDir}
-        ln -s ~{inputFile} ~{outputFile}
+        cp ~{inputFile} ~{outputFile}
         picard -Xmx~{javaXmx} \
             -XX:ParallelGCThreads=1 \
             CreateSequenceDictionary \