diff --git a/Code/Helper/NPOI.Helper/NPOI.Helper.csproj b/Code/Helper/NPOI.Helper/NPOI.Helper.csproj
index 2c549f2..ae0a469 100644
--- a/Code/Helper/NPOI.Helper/NPOI.Helper.csproj
+++ b/Code/Helper/NPOI.Helper/NPOI.Helper.csproj
@@ -33,8 +33,9 @@
     <DocumentationFile>..\..\ReleaseLib\Sadness.NPOI.Helper.XML</DocumentationFile>
   </PropertyGroup>
   <ItemGroup>
-    <Reference Include="BouncyCastle.Cryptography, Version=2.0.0.0, Culture=neutral, PublicKeyToken=072edcf4a5328938, processorArchitecture=MSIL">
-      <HintPath>..\..\packages\BouncyCastle.Cryptography.2.2.1\lib\net461\BouncyCastle.Cryptography.dll</HintPath>
+    <Reference Include="BouncyCastle.Cryptography, Version=2.0.0.0, Culture=neutral, PublicKeyToken=072edcf4a5328938">
+      <HintPath>..\..\packages/BouncyCastle.Cryptography.2.3.1/lib/net461/BouncyCastle.Cryptography.dll</HintPath>
+      <Private>True</Private>
     </Reference>
     <Reference Include="DocX, Version=1.0.0.22, Culture=neutral, processorArchitecture=MSIL">
       <HintPath>..\..\packages\DocX.1.0.0.22\lib\net40\DocX.dll</HintPath>
diff --git a/Code/Helper/NPOI.Helper/packages.config b/Code/Helper/NPOI.Helper/packages.config
index 5abd69d..90f8417 100644
--- a/Code/Helper/NPOI.Helper/packages.config
+++ b/Code/Helper/NPOI.Helper/packages.config
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="BouncyCastle.Cryptography" version="2.2.1" targetFramework="net48" />
+  <package id="BouncyCastle.Cryptography" version="2.3.1" targetFramework="net48" />
   <package id="DocX" version="1.0.0.22" targetFramework="net48" />
   <package id="Enums.NET" version="4.0.1" targetFramework="net48" />
   <package id="MathNet.Numerics.Signed" version="4.15.0" targetFramework="net48" />