diff --git a/CHANGES.txt b/CHANGES.txt
index 57cafba0..08a71419 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -5,6 +5,7 @@
 - NEW: it is now possible to reference existing resolver in resolver containers (IVY-35)
 - NEW: overwrite attribute in the publish task now let force overwrite of read only files (IVY-83) 
 - NEW: add a conflict manager ("strict") making build fail when a diamond conflict is found (thanks to Christer Jonsson) (IVY-118) 
+- IMPROVE: add possibility to avoid overwrite of an ivy variable when setting them in ivyconf.xml (IVY-127)
 - IMPROVE: ability to exclude the root project from the buildlist (thanks to Constantine Vetoshev) (IVY-124)
 - IMPROVE: exclusion of artifacts now works on transitive artifacts, and exclusion can specify organisation and/or module (IVY-116)
 - IMPROVE: now dynamic revisions replacement by deliver task can be turned off (IVY-120)
diff --git a/src/java/fr/jayasoft/ivy/Ivy.java b/src/java/fr/jayasoft/ivy/Ivy.java
index 2a501a9d..8d706baf 100644
--- a/src/java/fr/jayasoft/ivy/Ivy.java
+++ b/src/java/fr/jayasoft/ivy/Ivy.java
@@ -41,11 +41,9 @@ import org.xml.sax.SAXException;
 import fr.jayasoft.ivy.conflict.LatestConflictManager;
 import fr.jayasoft.ivy.conflict.NoConflictManager;
 import fr.jayasoft.ivy.conflict.StrictConflictManager;
-import fr.jayasoft.ivy.event.EndDownloadEvent;
 import fr.jayasoft.ivy.event.IvyEvent;
 import fr.jayasoft.ivy.event.IvyListener;
 import fr.jayasoft.ivy.event.PrepareDownloadEvent;
-import fr.jayasoft.ivy.event.StartDownloadEvent;
 import fr.jayasoft.ivy.filter.Filter;
 import fr.jayasoft.ivy.filter.FilterHelper;
 import fr.jayasoft.ivy.latest.LatestLexicographicStrategy;
@@ -299,19 +297,34 @@ public class Ivy implements TransferListener {
     }
 
     public void loadProperties(URL url) throws IOException {
+        loadProperties(url, true);
+    }
+    public void loadProperties(URL url, boolean overwrite) throws IOException {
         Properties properties = new Properties();
         properties.load(url.openStream());
-        addAllVariables(properties);
+        addAllVariables(properties, overwrite);
     }
     public void loadProperties(File file) throws IOException {
+        loadProperties(file, true);
+    }
+    
+    public void loadProperties(File file, boolean overwrite) throws IOException {
         Properties properties = new Properties();
         properties.load(new FileInputStream(file));
-        addAllVariables(properties);
+        addAllVariables(properties, overwrite);
     }
     
     public void setVariable(String varName, String value) {
-        Message.debug("setting '"+varName+"' to '"+value+"'");
-        _variables.put(varName, substitute(value));
+        setVariable(varName, value, true);
+    }
+    
+    public void setVariable(String varName, String value, boolean overwrite) {
+        if (overwrite || !_variables.containsKey(varName)) {
+            Message.debug("setting '"+varName+"' to '"+value+"'");
+            _variables.put(varName, substitute(value));
+        } else {
+            Message.debug("'"+varName+"' already set: discarding '"+value+"'");
+        }
     }
     
     public void addAllVariables(Map variables) {
@@ -321,10 +334,8 @@ public class Ivy implements TransferListener {
     public void addAllVariables(Map variables, boolean overwrite) {
         for (Iterator iter = variables.keySet().iterator(); iter.hasNext();) {
             String key = (String)iter.next();
-            if (overwrite || !_variables.containsKey(key)) {
-                String val = (String)variables.get(key);
-                setVariable(key, val);
-            }
+            String val = (String)variables.get(key);
+            setVariable(key, val, overwrite);
         }
     }
 
diff --git a/src/java/fr/jayasoft/ivy/xml/XmlIvyConfigurationParser.java b/src/java/fr/jayasoft/ivy/xml/XmlIvyConfigurationParser.java
index e61f08c8..d580257c 100644
--- a/src/java/fr/jayasoft/ivy/xml/XmlIvyConfigurationParser.java
+++ b/src/java/fr/jayasoft/ivy/xml/XmlIvyConfigurationParser.java
@@ -145,12 +145,13 @@ public class XmlIvyConfigurationParser extends DefaultHandler {
                 _ivy.setVariable(name, value);
             } else if ("properties".equals(qName)) {
                 String propFilePath = _ivy.substitute((String)attributes.get("file"));
+                String overwrite = _ivy.substitute((String)attributes.get("overwrite"));
                 try {
                     Message.verbose("loading properties: "+propFilePath);
-                    _ivy.loadProperties(new File(propFilePath));
+                    _ivy.loadProperties(new File(propFilePath), overwrite == null ? true : Boolean.valueOf(overwrite).booleanValue());
                 } catch (Exception ex) {
                     Message.verbose("failed to load properties as file: trying as url: "+propFilePath);
-                    _ivy.loadProperties(new URL(propFilePath));
+                    _ivy.loadProperties(new URL(propFilePath), overwrite == null ? true : Boolean.valueOf(overwrite).booleanValue());
                 }
             } else if ("include".equals(qName)) {
                 String propFilePath = _ivy.substitute((String)attributes.get("file"));