diff --git a/appveyor.yml b/appveyor.yml
index 31eaa0a3..03622207 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -5,6 +5,6 @@ install: []
 build_script:
 - set PATH=C:\Program Files (x86)\MSBuild\14.0\Bin;%PATH%
 - cmake .
-- msbuild json.sln
+- msbuild json.sln /p:Configuration=Release
 test_script:
-- Debug\json_unit.exe
+- Release\json_unit.exe