diff --git a/src/main/org/apache/tools/ant/taskdefs/Manifest.java b/src/main/org/apache/tools/ant/taskdefs/Manifest.java
index 06fc8e563..3f576c6e2 100644
--- a/src/main/org/apache/tools/ant/taskdefs/Manifest.java
+++ b/src/main/org/apache/tools/ant/taskdefs/Manifest.java
@@ -280,7 +280,7 @@ public class Manifest {
             Attribute attribute = null;
             while (true) { 
                 String line = reader.readLine();
-                if (line == null || line.length() == 0) {
+                if (line == null || line.trim().length() == 0) {
                     return null;
                 }
                 if (line.charAt(0) == ' ') {