diff --git a/brut.j.util/src/main/java/brut/util/Jar.java b/brut.j.util/src/main/java/brut/util/Jar.java
index eb0bffcc..96499001 100644
--- a/brut.j.util/src/main/java/brut/util/Jar.java
+++ b/brut.j.util/src/main/java/brut/util/Jar.java
@@ -85,19 +85,16 @@ abstract public class Jar {
             if (in == null) {
                 throw new FileNotFoundException(resourcePath);
             }
-            long n = ThreadLocalRandom.current().nextLong();
-            if (n == Long.MIN_VALUE) {
-                n = 0;      // corner case
-            } else {
-                n = Math.abs(n);
-            }
-            String suffix = Long.toString(n) + ".tmp";
-            File fileOut = File.createTempFile(tmpPrefix, suffix);
+            long suffix = ThreadLocalRandom.current().nextLong();
+            suffix = suffix == Long.MIN_VALUE ? 0 : Math.abs(suffix);
+            File fileOut = File.createTempFile(tmpPrefix, suffix + ".tmp");
             fileOut.deleteOnExit();
+
             OutputStream out = new FileOutputStream(fileOut);
             IOUtils.copy(in, out);
             in.close();
             out.close();
+
             return fileOut;
         } catch (IOException ex) {
             throw new BrutException("Could not extract resource: " + resourcePath, ex);