diff --git a/WHATSNEW b/WHATSNEW
index 0c91e8e45..88f54d7a1 100644
--- a/WHATSNEW
+++ b/WHATSNEW
@@ -40,6 +40,9 @@ Fixed bugs:
 * fix for junit4 issue introducted since beta2.
   Bugzilla report 40682.
 
+* Error in duplicate project name with <import> and <antcall>.
+  Bugzilla report 39920.
+
 Other changes:
 --------------
 
diff --git a/docs/manual/CoreTasks/import.html b/docs/manual/CoreTasks/import.html
index 533eb0956..63ec92f61 100644
--- a/docs/manual/CoreTasks/import.html
+++ b/docs/manual/CoreTasks/import.html
@@ -79,6 +79,10 @@ property of the main buildfile.</p>
 
 <p>Note that &quot;builddocs&quot; is not the filename, but the name attribute
 present in the imported project tag.</p>
+  <p>
+    If import file does not have a name attribute, the ant.file.projectname
+    property will not be set.
+  </p>
 
 <h4>Resolving files against the imported file</h4>
 
diff --git a/src/main/org/apache/tools/ant/helper/ProjectHelper2.java b/src/main/org/apache/tools/ant/helper/ProjectHelper2.java
index 78fa690fc..0450bf25f 100644
--- a/src/main/org/apache/tools/ant/helper/ProjectHelper2.java
+++ b/src/main/org/apache/tools/ant/helper/ProjectHelper2.java
@@ -738,7 +738,7 @@ public class ProjectHelper2 extends ProjectHelper {
                 }
             }
 
-            if (context.getBuildFile() != null) {
+            if (context.getBuildFile() != null && nameAttributeSet) {
                 project.setUserProperty("ant.file."
                     + context.getCurrentProjectName(),
                     context.getBuildFile().toString());