diff --git a/WHATSNEW b/WHATSNEW
index 7d95d12c9..6ffe7e646 100644
--- a/WHATSNEW
+++ b/WHATSNEW
@@ -275,6 +275,11 @@ Other changes:
 * The .NET compilation tasks failed if filenames given as references
   contained spaces.  Bugzilla Report 27170.
 
+* <macrodef> with default values set by properties would be
+  seen as new definitions when called twice with different properties.
+  This was confusing so the definitions are now treated as similar.
+  Bugzilla Report 31215.
+
 Fixed bugs:
 -----------
 
diff --git a/src/main/org/apache/tools/ant/taskdefs/MacroDef.java b/src/main/org/apache/tools/ant/taskdefs/MacroDef.java
index 79de27123..cc7f65081 100644
--- a/src/main/org/apache/tools/ant/taskdefs/MacroDef.java
+++ b/src/main/org/apache/tools/ant/taskdefs/MacroDef.java
@@ -716,6 +716,12 @@ public class MacroDef extends AntlibDefinition  {
         if (!name.equals(other.name)) {
             return false;
         }
+        // Allow two macro definitions with the same location
+        // to be treated as similar - bugzilla 31215
+        if (other.getLocation() != null
+            && other.getLocation().equals(getLocation())) {
+            return true;
+        }
         if (text == null) {
             if (other.text != null) {
                 return false;