diff --git a/src/pp_params.cr b/src/pp_params.cr
index d3ed6e6f41b79d5a8450e03f4fb7a65752c57046..8b7f6569d50b51640a61b5cee6e75a0276a3249f 100644
--- a/src/pp_params.cr
+++ b/src/pp_params.cr
@@ -14,7 +14,7 @@ class Job < JobHash
       next unless v
       v.each do |kk, vv|
         next unless vv
-        next if vv.starts_with?("_")  # skip config options that won't impact test result
+        next if kk.starts_with?("_")  # skip config options that won't impact test result
         temp_hash["#{k}.#{kk}"] = vv
       end
     end