diff --git workflow.module workflow.module
index 34b07d8..354ff32 100644
--- workflow.module
+++ workflow.module
@@ -107,6 +107,19 @@ function workflow_menu() {
   return $items;
 }
 
+ /*
+  * Determine authors of a given node.
+  */ 
+function workflow_get_authors($node) {
+  $authors = !empty($node->uid) ? array($node->uid => $node->uid) : array();
+  drupal_alter('workflow_authors',$authors,$node)  ;
+  if (is_array($authors)) {
+     return $authors; 
+  }
+  else {
+    return array();
+  }
+}
 /**
  * Menu access control callback. Determine access to Workflow tab.
  */
@@ -118,7 +131,7 @@ function workflow_node_tab_access($node = NULL) {
     return FALSE;
   }
   $roles = array_keys($user->roles);
-  if ($node->uid == $user->uid) {
+  if (in_array($user->uid, $workflow_get_authors($node))) {
     $roles = array_merge(array('author'), $roles);
   }
   $workflow = db_fetch_object(db_query("SELECT * FROM {workflows} WHERE wid = %d", $wid));
@@ -705,7 +718,7 @@ function workflow_field_choices($node) {
   $current_sid = workflow_node_current_state($node);
 
   // If user is node author or this is a new page, give the authorship role.
-  if (($user->uid == $node->uid && $node->uid > 0) || (arg(0) == 'node' && arg(1) == 'add')) {
+  if ((in_array($user->uid, workflow_get_authors($node))) || (arg(0) == 'node' && arg(1) == 'add')) {
     $roles += array('author' => 'author');
   }
   if ($user->uid == 1) {
diff --git workflow_access.module workflow_access.module
index 16d86ab..4d67536 100644
--- workflow_access.module
+++ workflow_access.module
@@ -32,15 +32,29 @@ function workflow_access_node_access_records($node) {
 
   // We have state information about this node, so get permissions for this state.
   if (is_numeric($sid)) {
+    $authors = workflow_get_authors($node);
     $result = db_query('SELECT * FROM {workflow_access} WHERE sid = %d', $sid);
     while ($grant = db_fetch_object($result)) {
-      $grants[] = array(
-        'realm'        => ($grant->rid == -1) ? 'workflow_access_owner' : 'workflow_access',
-        'gid'          => ($grant->rid == -1) ? $node->uid : $grant->rid,
-        'grant_view'   => $grant->grant_view,
-        'grant_update' => $grant->grant_update,
-        'grant_delete' => $grant->grant_delete
-      ); 
+      if ($grant->rid == -1 ) {
+        foreach($authors as $uid) { 
+           $grants[] = array(
+            'realm'        => 'workflow_access_owner' ,
+            'gid'          => $uid,
+            'grant_view'   => $grant->grant_view,
+            'grant_update' => $grant->grant_update,
+            'grant_delete' => $grant->grant_delete
+          );
+        }
+      } else {
+        $grants[] = array(
+            'realm'        =>'workflow_access',
+            'gid'          =>  $grant->rid,
+            'grant_view'   => $grant->grant_view,
+            'grant_update' => $grant->grant_update,
+            'grant_delete' => $grant->grant_delete
+          );
+      }
+ 
     }
   }