diff --git a/artefact.inc.php b/artefact.inc.php
index 6e9b0fd..f143264 100644
--- a/artefact.inc.php
+++ b/artefact.inc.php
@@ -89,8 +89,10 @@ class TaskmanArtefact
   {
     if(!isset($this->sources_affected[$idx]))
     {
-      $file_changes = $this->task->getFileChanges();
-      $sources = $file_changes != null ? $this->getChangedSources($idx) : $this->getSources($idx);
+      $sources = $this->task->getFileChanges() != null ? 
+        //tries to match changed files with sources spec
+        $this->getChangedSources($idx) : 
+        $this->getSources($idx);
       $this->sources_affected[$idx] = is_stale($this->getPath(), $sources);
     }
     
@@ -131,7 +133,10 @@ class TaskmanArtefact
         $this->setSourcesFn($src_idx, function() use($src_spec) {
           $dir2files = array();
           foreach($src_spec[0] as $spec_dir)
+          {
+            $spec_dir = normalize_path($spec_dir);
             $dir2files[$spec_dir] = scan_files([$spec_dir], $src_spec[1]);
+          }
           return new TaskmanDirFiles($dir2files); 
         });
 
@@ -141,6 +146,7 @@ class TaskmanArtefact
             $changed = array();
             foreach($src_spec[0] as $spec_dir)
             {
+              $spec_dir = normalize_path($spec_dir);
               $matches = $file_changes->matchDirectory($spec_dir, $src_spec[1]);
               $changed[$spec_dir] = $matches;
             }