diff --git a/src/main/java/org/caosdb/server/utils/FileUtils.java b/src/main/java/org/caosdb/server/utils/FileUtils.java
index 70ba003018e3ccc7831bf9f536e827552445ec6a..c07d43750ff36d3b495ca0e8ccb66ea8159af8a9 100644
--- a/src/main/java/org/caosdb/server/utils/FileUtils.java
+++ b/src/main/java/org/caosdb/server/utils/FileUtils.java
@@ -525,7 +525,7 @@ public class FileUtils {
   }
 
   private static void callPosixUnlink(File file) throws IOException, InterruptedException {
-    final Process cmd = Runtime.getRuntime().exec("unlink " + file.getAbsolutePath());
+    final Process cmd = Runtime.getRuntime().exec(new String[] {"unlink", file.getAbsolutePath()});
     if (cmd.waitFor() != 0) {
       throw new CaosDBException("could not unlink " + file.getAbsolutePath());
     }
@@ -539,7 +539,7 @@ public class FileUtils {
       @Override
       public void undo() {
         try {
-          Runtime.getRuntime().exec("ln -s " + path + " " + file.getAbsolutePath());
+          Runtime.getRuntime().exec(new String[] {"ln", "-s", path, file.getAbsolutePath()});
         } catch (final IOException e) {
           e.printStackTrace();
         }