diff --git a/lib/minimap2/aligner.rb b/lib/minimap2/aligner.rb
index 538173e..26394c7 100644
--- a/lib/minimap2/aligner.rb
+++ b/lib/minimap2/aligner.rb
@@ -80,8 +80,8 @@ def initialize(
         map_opt[:b] = scoring[1]
         map_opt[:q] = scoring[2]
         map_opt[:e] = scoring[3]
-        map_opt[:q2] = map_opt.q
-        map_opt[:e2] = map_opt.e
+        map_opt[:q2] = map_opt[:q]
+        map_opt[:e2] = map_opt[:e]
         if scoring.size >= 6
           map_opt[:q2] = scoring[4]
           map_opt[:e2] = scoring[5]