diff --git a/appveyor.yml b/appveyor.yml
index 169ee34e..7a98360c 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -22,9 +22,7 @@ install:
   - cd CGAL-4.11.1
   - mkdir build
   - cd build
-  - set GMP_INCLUDE_DIR=%APPVEYOR_BUILD_FOLDER%\CGAL-4.11.1\auxiliary\gmp\include
-  - set GMP_LIBRARIES=%APPVEYOR_BUILD_FOLDER%\CGAL-4.11.1\auxiliary\gmp\lib
-  - cmake ../
+  - cmake ../ -DGMP_INCLUDE_DIR=%APPVEYOR_BUILD_FOLDER%\CGAL-4.11.1\auxiliary\gmp\include -DGMP_LIBRARIES=%APPVEYOR_BUILD_FOLDER%\CGAL-4.11.1\auxiliary\gmp\lib
   - msbuild /p:Configuration=Release ALL_BUILD.vcxproj
     
 build: false