diff --git a/WHATSNEW b/WHATSNEW
index ad6a054b6..5fcca9d9a 100644
--- a/WHATSNEW
+++ b/WHATSNEW
@@ -7,6 +7,9 @@ Changes that could break older environments:
 Fixed bugs:
 -----------
 
+ * stack traces were not reported at all by <junit/>
+ when filtertrace="on", which is the default.
+
 Other changes:
 --------------
 
diff --git a/src/main/org/apache/tools/ant/taskdefs/optional/junit/JUnitTestRunner.java b/src/main/org/apache/tools/ant/taskdefs/optional/junit/JUnitTestRunner.java
index d483d13d2..feced5436 100644
--- a/src/main/org/apache/tools/ant/taskdefs/optional/junit/JUnitTestRunner.java
+++ b/src/main/org/apache/tools/ant/taskdefs/optional/junit/JUnitTestRunner.java
@@ -44,6 +44,7 @@ import junit.framework.TestSuite;
 import org.apache.tools.ant.BuildException;
 import org.apache.tools.ant.Project;
 import org.apache.tools.ant.types.Permissions;
+import org.apache.tools.ant.util.FileUtils;
 import org.apache.tools.ant.util.StringUtils;
 import org.apache.tools.ant.util.TeeOutputStream;
 
@@ -898,6 +899,8 @@ public class JUnitTestRunner implements TestListener, JUnitTaskMirror.JUnitTestR
             }
         } catch (Exception e) {
             return stack; // return the stack unfiltered
+        } finally {
+            FileUtils.close(pw);
         }
         return sw.toString();
     }