diff --git a/package/ci/appveyor-desktop-gles.bat b/package/ci/appveyor-desktop-gles.bat
index bd5ee13dc..3dda4e281 100644
--- a/package/ci/appveyor-desktop-gles.bat
+++ b/package/ci/appveyor-desktop-gles.bat
@@ -6,7 +6,7 @@ git clone --depth 1 git://github.com/mosra/corrade.git || exit /b
 cd corrade || exit /b
 mkdir build && cd build || exit /b
 cmake .. ^
-    -DCMAKE_BUILD_TYPE=Release ^
+    -DCMAKE_BUILD_TYPE=Debug ^
     -DCMAKE_INSTALL_PREFIX=%APPVEYOR_BUILD_FOLDER%/deps ^
     -DWITH_INTERCONNECT=OFF ^
     -G Ninja || exit /b
@@ -17,7 +17,7 @@ cd .. && cd ..
 rem Build
 mkdir build && cd build || exit /b
 cmake .. ^
-    -DCMAKE_BUILD_TYPE=Release ^
+    -DCMAKE_BUILD_TYPE=Debug ^
     -DCMAKE_INSTALL_PREFIX=%APPVEYOR_BUILD_FOLDER%/deps ^
     -DCMAKE_PREFIX_PATH="%APPVEYOR_BUILD_FOLDER%/openal" ^
     -DTARGET_GLES=ON ^
diff --git a/package/ci/appveyor-desktop.bat b/package/ci/appveyor-desktop.bat
index 8de5d0cd7..a7d55890e 100644
--- a/package/ci/appveyor-desktop.bat
+++ b/package/ci/appveyor-desktop.bat
@@ -6,7 +6,7 @@ git clone --depth 1 git://github.com/mosra/corrade.git || exit /b
 cd corrade || exit /b
 mkdir build && cd build || exit /b
 cmake .. ^
-    -DCMAKE_BUILD_TYPE=Release ^
+    -DCMAKE_BUILD_TYPE=Debug ^
     -DCMAKE_INSTALL_PREFIX=%APPVEYOR_BUILD_FOLDER%/deps ^
     -DWITH_INTERCONNECT=OFF ^
     -G Ninja || exit /b
@@ -17,7 +17,7 @@ cd .. && cd ..
 rem Build
 mkdir build && cd build || exit /b
 cmake .. ^
-    -DCMAKE_BUILD_TYPE=Release ^
+    -DCMAKE_BUILD_TYPE=Debug ^
     -DCMAKE_INSTALL_PREFIX=%APPVEYOR_BUILD_FOLDER%/deps ^
     -DCMAKE_PREFIX_PATH="%APPVEYOR_BUILD_FOLDER%/SDL;%APPVEYOR_BUILD_FOLDER%/openal" ^
     -DWITH_AUDIO=ON ^