diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3d96d21a8..395451b81 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -635,6 +635,7 @@ endfunction()
 file(MAKE_DIRECTORY "${PROJECT_BINARY_DIR}/src/game/generated/")
 execute_process(COMMAND git rev-parse --git-dir
   ERROR_QUIET
+  WORKING_DIRECTORY "${PROJECT_SOURCE_DIR}"
   OUTPUT_VARIABLE PROJECT_GIT_DIR
   OUTPUT_STRIP_TRAILING_WHITESPACE
   RESULT_VARIABLE PROJECT_GIT_DIR_ERROR