diff --git a/CPP/7zip/Archive/ZstdHandler.cpp b/CPP/7zip/Archive/ZstdHandler.cpp
index e5b0148f..b93e3f3a 100644
--- a/CPP/7zip/Archive/ZstdHandler.cpp
+++ b/CPP/7zip/Archive/ZstdHandler.cpp
@@ -286,6 +286,7 @@ static HRESULT UpdateArchive(
   CMyComPtr<ICompressProgressInfo> localProgress = localProgressSpec;
   localProgressSpec->Init(updateCallback, true);
   NCompress::NZSTD::CEncoder *encoderSpec = new NCompress::NZSTD::CEncoder;
+  encoderSpec->unpackSize = unpackSize;
   CMyComPtr<ICompressCoder> encoder = encoderSpec;
   RINOK(props.SetCoderProps(encoderSpec, NULL));
   RINOK(encoder->Code(fileInStream, outStream, NULL, NULL, localProgress));
diff --git a/CPP/7zip/Compress/ZstdEncoder.cpp b/CPP/7zip/Compress/ZstdEncoder.cpp
index bf5c8fa4..b7c6543e 100644
--- a/CPP/7zip/Compress/ZstdEncoder.cpp
+++ b/CPP/7zip/Compress/ZstdEncoder.cpp
@@ -30,7 +30,8 @@ CEncoder::CEncoder():
   _LdmHashLog(-1),
   _LdmMinMatch(-1),
   _LdmBucketSizeLog(-1),
-  _LdmHashRateLog(-1)
+  _LdmHashRateLog(-1),
+  unpackSize(0)
 {
   _props.clear();
 }
@@ -251,6 +252,11 @@ STDMETHODIMP CEncoder::Code(ISequentialInStream *inStream,
     err = ZSTD_CCtx_setParameter(_ctx, ZSTD_c_contentSizeFlag, 1);
     if (ZSTD_isError(err)) return E_INVALIDARG;
 
+    if (unpackSize) {
+      err = ZSTD_CCtx_setParameter(_ctx, ZSTD_c_srcSizeHint, (int)(unpackSize <= INT_MAX ? unpackSize : INT_MAX));
+      if (ZSTD_isError(err)) return E_INVALIDARG;
+    }
+
     /* enable ldm for large windowlog values */
     if (_WindowLog > 27 && _Long == 0)
       _Long = 1;
diff --git a/CPP/7zip/Compress/ZstdEncoder.h b/CPP/7zip/Compress/ZstdEncoder.h
index 56fe0671..814bdad0 100644
--- a/CPP/7zip/Compress/ZstdEncoder.h
+++ b/CPP/7zip/Compress/ZstdEncoder.h
@@ -67,6 +67,9 @@ class CEncoder:
   Int32 _LdmHashRateLog;
 
 public:
+
+  UInt64 unpackSize;
+
   MY_QUERYINTERFACE_BEGIN2(ICompressCoder)
   MY_QUERYINTERFACE_ENTRY(ICompressSetCoderMt)
   MY_QUERYINTERFACE_ENTRY(ICompressSetCoderProperties)