diff --git a/letsencrypt-win-simple/packages.config b/letsencrypt-win-simple/packages.config
index 972ef5f10..ef54bf6aa 100644
--- a/letsencrypt-win-simple/packages.config
+++ b/letsencrypt-win-simple/packages.config
@@ -81,7 +81,7 @@
   <package id="System.ServiceProcess.ServiceController" version="4.4.0" targetFramework="net461" />
   <package id="System.Text.Encoding" version="4.3.0" targetFramework="net461" />
   <package id="System.Text.Encoding.Extensions" version="4.3.0" targetFramework="net461" />
-  <package id="System.Text.RegularExpressions" version="4.3.0" targetFramework="net461" />
+  <package id="System.Text.RegularExpressions" version="4.3.1" targetFramework="net461" />
   <package id="System.Threading" version="4.3.0" targetFramework="net461" />
   <package id="System.Threading.Tasks" version="4.3.0" targetFramework="net461" />
   <package id="System.Threading.Timer" version="4.3.0" targetFramework="net461" />