diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4985ae3..6142069 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,8 @@
 
 ## v3.2.2
 
-- Optimize: speed up drastically.
+- Optimize: speed up for threads <= 2.
+- Fix: `atria test` should not depend on source files.
 
 ## v3.2.1
 
diff --git a/src/Trimmer/wrapper.jl b/src/Trimmer/wrapper.jl
index fb2edaa..62ee9c8 100644
--- a/src/Trimmer/wrapper.jl
+++ b/src/Trimmer/wrapper.jl
@@ -578,11 +578,11 @@ function julia_wrapper_atria(ARGS::Vector{String}; exit_after_help = true)
         end
 
         if outcompress == "GZIP"
-            io1out = open(`pigz -p$nthread -c`, open(outfile1, "w"), write=true, read=false)
-            io2out = open(`pigz -p$nthread -c`, open(outfile2, "w"), write=true, read=false)
+            io1out = open(`pigz -p$halfthread -c`, open(outfile1, "w"), write=true, read=false)
+            io2out = open(`pigz -p$halfthread -c`, open(outfile2, "w"), write=true, read=false)
         elseif outcompress == "BZIP2"
-            io1out = open(`pbzip2 -p$nthread -c`, open(outfile1, "w"), write=true, read=false)
-            io2out = open(`pbzip2 -p$nthread -c`, open(outfile2, "w"), write=true, read=false)
+            io1out = open(`pbzip2 -p$halfthread -c`, open(outfile1, "w"), write=true, read=false)
+            io2out = open(`pbzip2 -p$halfthread -c`, open(outfile2, "w"), write=true, read=false)
         else
             io1out = open(outfile1, "w")
             io2out = open(outfile2, "w")