diff --git a/appveyor.yml b/appveyor.yml
index 854b634e85..f7f4b1a412 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -77,8 +77,9 @@ after_build:
     copy-item compat_database.dat .\bin\GuiConfigs\compat_database.dat
 
 - ps: | # package artifacts
-    7z a $env:BUILD .\bin\*
-    7z a openssl_win64.7z C:\OpenSSL-Win64\bin\libeay32.dll C:\OpenSSL-Win64\bin\ssleay32.dll
+    7z a -m0=LZMA2 -mx9 $env:BUILD .\bin\*
+    7z a -m0=LZMA2 -mx9 openssl_win64.7z C:\OpenSSL-Win64\bin\libeay32.dll `
+      C:\OpenSSL-Win64\bin\ssleay32.dll
 
 test: off