diff --git a/CMakeLists.txt b/CMakeLists.txt
index c4405d15..6a348c5d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -25,9 +25,11 @@ if(DEFINED COLOBOT_VERSION_UNRELEASED)
     if(EXISTS "${CMAKE_SOURCE_DIR}/.git")
         find_package(Git)
         execute_process(COMMAND ${GIT_EXECUTABLE} rev-parse --abbrev-ref HEAD
+                        WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}"
                         OUTPUT_VARIABLE GIT_BRANCH
                         OUTPUT_STRIP_TRAILING_WHITESPACE)
         execute_process(COMMAND ${GIT_EXECUTABLE} rev-parse --short HEAD
+                        WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}"
                         OUTPUT_VARIABLE GIT_REVISION
                         OUTPUT_STRIP_TRAILING_WHITESPACE)
         set(COLOBOT_VERSION_UNRELEASED "${COLOBOT_VERSION_UNRELEASED}-git-${GIT_BRANCH}~r${GIT_REVISION}")