diff --git a/src/etc/testcases/taskdefs/optional/junit.xml b/src/etc/testcases/taskdefs/optional/junit.xml
index 721bd8874..afc665465 100644
--- a/src/etc/testcases/taskdefs/optional/junit.xml
+++ b/src/etc/testcases/taskdefs/optional/junit.xml
@@ -258,4 +258,20 @@
     </echo>
   </target>
   
+  <!-- Bugzilla Issue 45411 -->
+  <target name="testMultilineAssertsNoFork">
+    <junit>
+      <test name="org.example.junit.MultilineAsserts"/>
+      <classpath refid="test"/>
+    </junit>
+  </target>
+
+  <!-- Bugzilla Issue 45411 -->
+  <target name="testMultilineAssertsFork">
+    <junit fork="true">
+      <test name="org.example.junit.MultilineAsserts"/>
+      <classpath refid="test"/>
+    </junit>
+  </target>
+
 </project>
diff --git a/src/tests/junit/org/apache/tools/ant/BuildFileTest.java b/src/tests/junit/org/apache/tools/ant/BuildFileTest.java
index 18ae9bd27..715a396da 100644
--- a/src/tests/junit/org/apache/tools/ant/BuildFileTest.java
+++ b/src/tests/junit/org/apache/tools/ant/BuildFileTest.java
@@ -115,6 +115,16 @@ public abstract class BuildFileTest extends TestCase {
                    realLog.indexOf(substring) >= 0);
     }
 
+    /**
+     * Assert that the given substring is not in the log messages.
+     */
+    public void assertLogNotContaining(String substring) {
+        String realLog = getLog();
+        assertFalse("didn't expect log to contain \"" + substring + "\" log was \""
+                    + realLog + "\"",
+                    realLog.indexOf(substring) >= 0);
+    }
+
     /**
      * Assert that the given substring is in the output messages.
      * @since Ant1.7
@@ -160,6 +170,15 @@ public abstract class BuildFileTest extends TestCase {
         assertLogContaining(log);
     }
 
+    /**
+     * Assert that the given message has not been logged with a
+     * priority &lt;= INFO when running the given target.
+     */
+    public void expectLogNotContaining(String target, String log) {
+        executeTarget(target);
+        assertLogNotContaining(log);
+    }
+
     /**
      * Gets the log the BuildFileTest object.
      * Only valid if configureProject() has been called.
diff --git a/src/tests/junit/org/apache/tools/ant/taskdefs/optional/junit/JUnitTaskTest.java b/src/tests/junit/org/apache/tools/ant/taskdefs/optional/junit/JUnitTaskTest.java
index a8fc76d8b..3e428b8e2 100644
--- a/src/tests/junit/org/apache/tools/ant/taskdefs/optional/junit/JUnitTaskTest.java
+++ b/src/tests/junit/org/apache/tools/ant/taskdefs/optional/junit/JUnitTaskTest.java
@@ -216,11 +216,22 @@ public class JUnitTaskTest extends BuildFileTest {
         }
     }
 
-
     public void testBatchTestForkOnceCustomFormatter() {
         assertResultFilesExist("testBatchTestForkOnceCustomFormatter", "foo");
     }
 
+    // Bugzilla Issue 45411
+    public void testMultilineAssertsNoFork() {
+        expectLogNotContaining("testMultilineAssertsNoFork", "messed up)");
+        assertLogNotContaining("crashed)");
+    }
+
+    // Bugzilla Issue 45411
+    public void XtestMultilineAssertsFork() {
+        expectLogNotContaining("testMultilineAssertsFork", "messed up)");
+        assertLogNotContaining("crashed)");
+    }
+
     private void assertResultFilesExist(String target, String extension) {
         executeTarget(target);
         assertResultFileExists("JUnitClassLoader", extension);
diff --git a/src/tests/junit/org/example/junit/MultilineAsserts.java b/src/tests/junit/org/example/junit/MultilineAsserts.java
new file mode 100644
index 000000000..06e10390d
--- /dev/null
+++ b/src/tests/junit/org/example/junit/MultilineAsserts.java
@@ -0,0 +1,27 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+package org.example.junit;
+
+import junit.framework.TestCase;
+
+public class MultilineAsserts extends TestCase {
+    public void testFoo() { assertTrue("testFoo \nmessed up", false); }
+    public void testBar() { assertTrue("testBar \ndidn't work", true); }
+    public void testFee() { assertTrue("testFee \ncrashed", false); }
+    public void testFie() { assertTrue("testFie \nbroke", true); }
+}