1 files changed, 9 insertions, 1 deletions
diff --git a/CPP/7zip/Archive/Zip/ZipUpdate.cpp b/CPP/7zip/Archive/Zip/ZipUpdate.cpp
index 3294ad78..403b5efe 100755
--- a/CPP/7zip/Archive/Zip/ZipUpdate.cpp
+++ b/CPP/7zip/Archive/Zip/ZipUpdate.cpp
@@ -1,4 +1,4 @@
-// ZipUpdate.cpp
+lzma// ZipUpdate.cpp
 
 #include "StdAfx.h"
 
@@ -568,6 +568,14 @@ static HRESULT Update2(
       if (numThreads <= 1)
         mtMode = false;
     }
+    if (method == NFileHeader::NCompressionMethod::kLZMA)
+    {
+      UInt32 numLZMAThreads = (options->Algo > 0 ? 2 : 1);
+      numThreads /= numLZMAThreads;
+      options2.NumThreads = numLZMAThreads;
+      if (numThreads <= 1)
+        mtMode = false;
+    }
   }
 
   if (!mtMode)