diff --git a/src/kilim/tools/Javac.java b/src/kilim/tools/Javac.java
index 5d001087..770fbce7 100644
--- a/src/kilim/tools/Javac.java
+++ b/src/kilim/tools/Javac.java
@@ -4,6 +4,7 @@
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.security.SecureRandom;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Random;
@@ -102,7 +103,7 @@ private static File getTmpDir() throws IOException {
         } else {
             tmpDirName += File.separator;
         }
-        Random r = new Random();
+        Random r = new SecureRandom();
         String name = tmpDirName + "kilim$" + r.nextLong();
         File rootDir = new File(name);
         if (!rootDir.mkdir()) {
diff --git a/test/kilim/test/TestRing.java b/test/kilim/test/TestRing.java
index 97ebefee..72b6b480 100644
--- a/test/kilim/test/TestRing.java
+++ b/test/kilim/test/TestRing.java
@@ -1,5 +1,6 @@
 package kilim.test;
 
+import java.security.SecureRandom;
 import junit.framework.TestCase;
 
 import java.util.Random;
@@ -39,7 +40,7 @@ public void testBoundedQueue() {
     }
 
     private Integer[] mkRandom() {
-        Random r = new Random();
+        Random r = new SecureRandom();
         Integer[] ret = new Integer[1000];
         for (int i = 0; i < 1000; i++) {
             ret[i] = new Integer(r.nextInt(1000));