diff --git a/src/main/org/apache/tools/ant/property/ResolvePropertyMap.java b/src/main/org/apache/tools/ant/property/ResolvePropertyMap.java
index 11468135c..ea0caf6e9 100644
--- a/src/main/org/apache/tools/ant/property/ResolvePropertyMap.java
+++ b/src/main/org/apache/tools/ant/property/ResolvePropertyMap.java
@@ -35,6 +35,7 @@ public class ResolvePropertyMap implements GetProperty {
     private final ParseProperties parseProperties;
     private final GetProperty master;
     private Map map;
+    private String prefix;
 
     /**
      * Constructor with a master getproperty and a collection of expanders.
@@ -57,6 +58,19 @@ public class ResolvePropertyMap implements GetProperty {
             throw new BuildException(
                 "Property " + name + " was circularly " + "defined.");
         }
+
+        // if the property has already been set to the name it will
+        // have in the end, then return the existing value to ensure
+        // properties remain immutable
+        String masterPropertyName = name;
+        if (prefix != null) {
+            masterPropertyName = prefix + name;
+        }
+        Object masterProperty = master.getProperty(masterPropertyName);
+        if (masterProperty != null) {
+            return masterProperty;
+        }
+
         try {
             seen.add(name);
             return parseProperties.parseProperties((String) map.get(name));
@@ -68,9 +82,21 @@ public class ResolvePropertyMap implements GetProperty {
     /**
      * The action method - resolves all the properties in a map.
      * @param map the map to resolve properties in.
+     * @deprecated since Ant 1.8.1, use the two-arg method instead.
      */
     public void resolveAllProperties(Map map) {
+        resolveAllProperties(map, null);
+    }
+
+    /**
+     * The action method - resolves all the properties in a map.
+     * @param map the map to resolve properties in.
+     * @param prefix the prefix the properties defined inside the map
+     * will finally receive - may be null.
+     */
+    public void resolveAllProperties(Map map, String prefix) {
         this.map = map; // The map gets used in the getProperty callback
+        this.prefix = prefix;
         for (Iterator i = map.keySet().iterator(); i.hasNext();) {
             String key = (String) i.next();
             Object result = getProperty(key);
diff --git a/src/main/org/apache/tools/ant/taskdefs/Property.java b/src/main/org/apache/tools/ant/taskdefs/Property.java
index 1b2bd4e6b..f84348247 100644
--- a/src/main/org/apache/tools/ant/taskdefs/Property.java
+++ b/src/main/org/apache/tools/ant/taskdefs/Property.java
@@ -715,7 +715,8 @@ public class Property extends Task {
         new ResolvePropertyMap(
                                getProject(),
                                propertyHelper,
-                               propertyHelper.getExpanders()).resolveAllProperties(props);
+                               propertyHelper.getExpanders())
+            .resolveAllProperties(props, prefix);
     }
 
 }
diff --git a/src/tests/antunit/taskdefs/property-test.xml b/src/tests/antunit/taskdefs/property-test.xml
index 3a3e10a60..77d23608c 100644
--- a/src/tests/antunit/taskdefs/property-test.xml
+++ b/src/tests/antunit/taskdefs/property-test.xml
@@ -77,4 +77,15 @@
     <property name="foo" location="${testfile}" relative="true" basedir=".."/>
     <au:assertPropertyEquals name="foo" value="taskdefs${file.separator}${testfile}"/>
   </target>
+
+  <target name="testNestedExpansionHonorsImmutability">
+    <mkdir dir="${input}"/>
+    <property name="x" value="x"/>
+    <echo file="${input}/x.properties"><![CDATA[
+x=y
+y=$${x}
+]]></echo>
+    <property file="${input}/x.properties"/>
+    <au:assertPropertyEquals name="y" value="x"/>
+  </target>
 </project>