diff --git a/appveyor.yml b/appveyor.yml
index ac9438f1..77fec70f 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -45,23 +45,23 @@ platform:
 environment:
   matrix:
   - SOL2_LUA_VERSION: luajit-2.0.5
-    SOL2_NO_2015: 1
     SOL2_BUILD_NINJA: 1
+    SOL2_NO_2015: 1
   - SOL2_LUA_VERSION: luajit-2.1.0-beta3
-    SOL2_NO_2015: 1
     SOL2_BUILD_NINJA: 1
+    SOL2_NO_2015: 1
   - SOL2_LUA_VERSION: 5.3.5
+    SOL2_BUILD_NINJA: 1
     MINGW_VERSION: 7.3.0
-    SOL2_BUILD_NINJA: 1
   - SOL2_LUA_VERSION: 5.3.5
-    MINGW_VERSION: 8.1.0
     SOL2_BUILD_NINJA: 1
+    MINGW_VERSION: 8.1.0
   - SOL2_LUA_VERSION: luajit-2.0.5
-    MINGW_VERSION: 8.1.0
     SOL2_BUILD_NINJA: 1
+    MINGW_VERSION: 8.1.0
   - SOL2_LUA_VERSION: luajit-2.1.0-beta3
-    MINGW_VERSION: 8.1.0
     SOL2_BUILD_NINJA: 1
+    MINGW_VERSION: 8.1.0
   - SOL2_LUA_VERSION: 5.3.5
     SOL2_NO_2015: 1
   - SOL2_LUA_VERSION: 5.2.4
@@ -154,7 +154,7 @@ init:
 before_build:
 - md build-sol2
 - cd build-sol2
-- if "%MINGW_VERSION%"=="" ( %vcvars_script% )
+- if not defined MINGW_VERSION ( %vcvars_script% )
 - cmake .. -G "%CMAKE_GENERATOR%" %build_compiler% -DCMAKE_BUILD_TYPE=Release "-DSOL2_LUA_VERSION=%SOL2_LUA_VERSION%" -DSOL2_PLATFORM=%PLATFORM% -DSOL2_CI=ON -DSOL2_BUILD_LUA=ON -DBUILD_LUA_AS_DLL=ON -DSOL2_TESTS=ON -DSOL2_EXAMPLES=ON -DSOL2_TESTS_EXAMPLES=ON 
 
 build_script: