diff --git a/build.xml b/build.xml
index c16dcda17..7818609b8 100644
--- a/build.xml
+++ b/build.xml
@@ -593,6 +593,13 @@
     <condition property="running.in.gump">
       <isset property="gump.merge"/>
     </condition>
+
+    <condition property="build.compiler" value="classic">
+      <not>
+        <isset property="jdk1.3+"/>
+      </not>
+    </condition>
+    <property name="build.compiler" value="modern"/>
   </target>
 
 
@@ -1473,6 +1480,7 @@
       <sysproperty key="tests-classpath.value"
                    value="${tests-classpath.value}"/>
       <sysproperty key="root" file="${basedir}"/>
+      <sysproperty key="build.compiler" value="${build.compiler}"/>
 
       <formatter type="brief" usefile="false"/>
 
@@ -1633,6 +1641,7 @@
       <sysproperty key="tests-classpath.value"
                    value="${tests-classpath.value}"/>
       <sysproperty key="root" file="${basedir}"/>
+      <sysproperty key="build.compiler" value="${build.compiler}"/>
       <classpath refid="tests-classpath"/>
       <formatter type="plain" usefile="false"/>
       <test name="${testcase}"/>
diff --git a/src/testcases/org/apache/tools/ant/taskdefs/JavacTest.java b/src/testcases/org/apache/tools/ant/taskdefs/JavacTest.java
index 018da11ce..53a247b2e 100644
--- a/src/testcases/org/apache/tools/ant/taskdefs/JavacTest.java
+++ b/src/testcases/org/apache/tools/ant/taskdefs/JavacTest.java
@@ -144,13 +144,18 @@ public class JavacTest extends TestCase {
         // check defaults
         String compiler = javac.getCompiler();
         assertNotNull(compiler);
-        assertTrue("default value",
-                   "javac1.1".equals(compiler)
-                   || "javac1.2".equals(compiler)
-                   || "javac1.3".equals(compiler)
-                   || "javac1.4".equals(compiler)
-                   || "javac1.5".equals(compiler)
-                   || "classic".equals(compiler));
+        if (System.getProperty("build.compiler") != null) {
+            assertEquals(System.getProperty("build.compiler"),
+                         compiler);
+        } else {
+            assertTrue("default value",
+                       "javac1.1".equals(compiler)
+                       || "javac1.2".equals(compiler)
+                       || "javac1.3".equals(compiler)
+                       || "javac1.4".equals(compiler)
+                       || "javac1.5".equals(compiler)
+                       || "classic".equals(compiler));
+        }
 
         javac.setFork(true);
         assertNotNull(javac.getCompiler());
@@ -160,7 +165,8 @@ public class JavacTest extends TestCase {
         // check build.compiler provides defaults
         javac = new Javac();
         javac.setProject(project);
-        project.setNewProperty("build.compiler", "jikes");
+        // setUserProperty to override system properties
+        project.setUserProperty("build.compiler", "jikes");
         compiler = javac.getCompiler();
         assertNotNull(compiler);
         assertEquals("jikes", compiler);