diff --git a/CMake/platforms/ctr/asio_defs.cmake b/CMake/platforms/ctr/asio_defs.cmake
index 6f180963d..3dae2d872 100644
--- a/CMake/platforms/ctr/asio_defs.cmake
+++ b/CMake/platforms/ctr/asio_defs.cmake
@@ -3,4 +3,4 @@ target_compile_definitions(asio INTERFACE
   ASIO_HAS_UNISTD_H=ON)
 
 # Missing headers and declarations provided by DevilutionX
-target_include_directories(asio BEFORE INTERFACE ${DevilutionX_SOURCE_DIR}/Source/platform/ctr/asio/include)
+target_include_directories(asio BEFORE INTERFACE ${PROJECT_SOURCE_DIR}/Source/platform/ctr/asio/include)
diff --git a/CMake/platforms/switch/asio_defs.cmake b/CMake/platforms/switch/asio_defs.cmake
index 1000f786b..42826df2c 100644
--- a/CMake/platforms/switch/asio_defs.cmake
+++ b/CMake/platforms/switch/asio_defs.cmake
@@ -2,4 +2,4 @@
 target_compile_definitions(asio INTERFACE _DEFAULT_SOURCE=ON)
 
 # Missing headers and declarations provided by DevilutionX
-target_include_directories(asio BEFORE INTERFACE ${DevilutionX_SOURCE_DIR}/Source/platform/switch/asio/include)
+target_include_directories(asio BEFORE INTERFACE ${PROJECT_SOURCE_DIR}/Source/platform/switch/asio/include)