diff --git a/build.xml b/build.xml
index a82f1ca1a..ca74b40f6 100644
--- a/build.xml
+++ b/build.xml
@@ -397,7 +397,7 @@
   <target name="check_for_optional_packages">
     <available property="jdk1.3+" classname="java.lang.StrictMath"/>
     <available property="jdk1.4+" classname="java.lang.CharSequence"/>
-    <available property="jdk1.5+" classname="java.lang.Readable"/>
+    <available property="jdk1.5+" classname="java.net.Proxy"/>
     <available property="jdk1.6+" classname="java.util.Service"/>
     <available property="kaffe" classname="kaffe.util.NotImplemented"/>
     <available property="bsf.present"
diff --git a/src/main/org/apache/tools/ant/util/JavaEnvUtils.java b/src/main/org/apache/tools/ant/util/JavaEnvUtils.java
index 26c327245..bbebbc6ce 100644
--- a/src/main/org/apache/tools/ant/util/JavaEnvUtils.java
+++ b/src/main/org/apache/tools/ant/util/JavaEnvUtils.java
@@ -79,7 +79,7 @@ public final class JavaEnvUtils {
     static {
 
         // Determine the Java version by looking at available classes
-        // java.lang.Readable was introduced in JDK 1.5
+        // java.net.Proxy was introduced in JDK 1.5
         // java.lang.CharSequence was introduced in JDK 1.4
         // java.lang.StrictMath was introduced in JDK 1.3
         // java.lang.ThreadLocal was introduced in JDK 1.2