diff --git a/CHANGES.txt b/CHANGES.txt
index 1f4b4715..1985a176 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,3 +1,4 @@
+- FIX: raise a clean error when a cyclic variable definition is found (IVY-75)
 - FIX: reinitiliase ant project instance at each new task to avoid using a bad ant project instance in some ide (like netbeans) (IVY-87)
 - FIX: ivy is now able to use simple ivy files in cache (doesn't need resolver info, use default one if no resolver is given) (IVY-86)
 - FIX: private conf not accessible from other modules (IVY-76)
diff --git a/src/java/fr/jayasoft/ivy/util/IvyPatternHelper.java b/src/java/fr/jayasoft/ivy/util/IvyPatternHelper.java
index 8d6a85c1..63008d2e 100644
--- a/src/java/fr/jayasoft/ivy/util/IvyPatternHelper.java
+++ b/src/java/fr/jayasoft/ivy/util/IvyPatternHelper.java
@@ -5,8 +5,11 @@
  */
 package fr.jayasoft.ivy.util;
 
+import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
+import java.util.Stack;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -83,11 +86,15 @@ public class IvyPatternHelper {
     }
     
     public static String substituteVariables(String pattern, Map variables) {
-    	// if you supply null, null is what you get
-    	if (pattern == null) {
-    		return null;
-    	}
-    	
+        return substituteVariables(pattern, variables, new Stack());
+    }
+    
+    private static String substituteVariables(String pattern, Map variables, Stack substituting) {
+        // if you supply null, null is what you get
+        if (pattern == null) {
+            return null;
+        }
+        
         Matcher m = VAR_PATTERN.matcher(pattern);
         
         StringBuffer sb = new StringBuffer();
@@ -95,7 +102,15 @@ public class IvyPatternHelper {
             String var = m.group(1);
             String val = (String)variables.get(var);
             if (val != null) {
-                val = substituteVariables(val, variables);
+                int index;
+                if ((index = substituting.indexOf(var)) != -1) {
+                    List cycle = new ArrayList(substituting.subList(index, substituting.size()));
+                    cycle.add(var);
+                    throw new IllegalArgumentException("cyclic variable definition: cycle = "+cycle);
+                }
+                substituting.push(var);
+                val = substituteVariables(val, variables, substituting);
+                substituting.pop();
             } else {
                 val = m.group();
             }
diff --git a/test/java/fr/jayasoft/ivy/util/IvyPatternHelperTest.java b/test/java/fr/jayasoft/ivy/util/IvyPatternHelperTest.java
index 2196b801..4b2f1291 100644
--- a/test/java/fr/jayasoft/ivy/util/IvyPatternHelperTest.java
+++ b/test/java/fr/jayasoft/ivy/util/IvyPatternHelperTest.java
@@ -6,6 +6,9 @@
  */
 package fr.jayasoft.ivy.util;
 
+import java.util.HashMap;
+import java.util.Map;
+
 import junit.framework.TestCase;
 
 public class IvyPatternHelperTest extends TestCase {
@@ -16,6 +19,21 @@ public class IvyPatternHelperTest extends TestCase {
                 IvyPatternHelper.substitute(pattern, "jayasoft", "Test", "1.0", "test", "jar", "jar"));
     }
 
+    public void testCyclicSubstitute() {
+        String pattern = "${var}";
+        Map variables = new HashMap();
+        variables.put("var", "${othervar}");
+        variables.put("othervar", "${var}");
+        try {
+            IvyPatternHelper.substituteVariables(pattern, variables);
+            fail("cyclic var should raise an exception");
+        } catch (Exception ex) {
+            // ok
+        } catch (Error er) {
+            fail("cyclic var shouldn't raise an error: "+er);
+        }
+    }
+
     public void testOrganization() {
         String pattern = "[organization]/[module]/build/archives/[type]s/[artifact]-[revision].[ext]";
         assertEquals(