diff --git a/modules/aeolus/aeolus_amv.py b/modules/aeolus/aeolus_amv.py
index 969fd0a8ea322f0dc6143e800d2688c43d84329d..0f2bbb142c56905ac0995eae2cd544121817ce83 100644
--- a/modules/aeolus/aeolus_amv.py
+++ b/modules/aeolus/aeolus_amv.py
@@ -253,7 +253,7 @@ def run_best_fit_driver(amv_dir, source, raob_path, gfs_path, product_dir, produ
     raob_ds = get_datasource(raob_path, 'RAOB')
     raob_files = raob_ds.flist
     prd_files = None
-    if product_dir is None:
+    if product_dir is not None:
         prd_files = get_datasource(product_dir, product)
 
     out_list = []