diff --git a/src/main/java/org/codehaus/plexus/archiver/AbstractArchiver.java b/src/main/java/org/codehaus/plexus/archiver/AbstractArchiver.java
index 8b4bdfa5f..c6b1b5577 100755
--- a/src/main/java/org/codehaus/plexus/archiver/AbstractArchiver.java
+++ b/src/main/java/org/codehaus/plexus/archiver/AbstractArchiver.java
@@ -450,7 +450,7 @@ protected ArchiveEntry asArchiveEntry( @Nonnull final PlexusIoResource resource,
             throw new ArchiverException( resource.getName() + " not found." );
         }
 
-        if ( umask > 0 )
+        if ( umask > 0 && permissions != PlexusIoResourceAttributes.UNKNOWN_OCTAL_MODE )
         {
             permissions &= ~umask;
         }