diff --git a/src/java/org/apache/ivy/core/module/id/ModuleRevisionId.java b/src/java/org/apache/ivy/core/module/id/ModuleRevisionId.java
index aab42833..89a6ad7e 100644
--- a/src/java/org/apache/ivy/core/module/id/ModuleRevisionId.java
+++ b/src/java/org/apache/ivy/core/module/id/ModuleRevisionId.java
@@ -20,6 +20,7 @@ package org.apache.ivy.core.module.id;
 import java.lang.ref.WeakReference;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.TreeMap;
 import java.util.WeakHashMap;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -259,7 +260,7 @@ public class ModuleRevisionId extends UnmodifiableExtendableItem {
 
     public String encodeToString() {
         StringBuilder buf = new StringBuilder();
-        Map<String, String> attributes = new HashMap<>(getAttributes());
+        Map<String, String> attributes = new TreeMap<>(getAttributes());
         attributes.keySet().removeAll(getExtraAttributes().keySet());
         attributes.putAll(getQualifiedExtraAttributes());
 
diff --git a/test/java/org/apache/ivy/core/module/id/ModuleRevisionIdTest.java b/test/java/org/apache/ivy/core/module/id/ModuleRevisionIdTest.java
index 9a7667e6..5af34d4f 100644
--- a/test/java/org/apache/ivy/core/module/id/ModuleRevisionIdTest.java
+++ b/test/java/org/apache/ivy/core/module/id/ModuleRevisionIdTest.java
@@ -85,6 +85,12 @@ public class ModuleRevisionIdTest {
         extraAttributes.put("nullatt", null);
         testEncodeDecodeToString(
             ModuleRevisionId.newInstance("org/apache", "pre/name", "1.0-dev8/2", extraAttributes));
+
+        String encoded = ModuleRevisionId.newInstance("org/apache", "pre/name", "1.0-dev8/2", extraAttributes).encodeToString();
+        // We expect the encoding/ordering to be stable for reproducibility.
+        // If necessary this may vary across Ivy versions,
+        // but ideally only intentionally.
+        assertEquals("+att.name:#@#:+att.value:#@#:+att/name:#@#:+att/value:#@#:+att<name:#@#:+att<value:#@#:+branch:#@#:+@#:NULL:#@:#@#:+extra:#@#:+extravalue:#@#:+module:#@#:+pre/name:#@#:+nullatt:#@#:+@#:NULL:#@:#@#:+organisation:#@#:+org/apache:#@#:+revision:#@#:+1.0-dev8/2:#@#:", encoded);
     }
 
     private void testEncodeDecodeToString(ModuleRevisionId mrid) {