diff --git a/cpp/CMakeLists.txt b/cpp/CMakeLists.txt
index 9b1c6d1b..973e771d 100644
--- a/cpp/CMakeLists.txt
+++ b/cpp/CMakeLists.txt
@@ -36,7 +36,13 @@ else()
 endif()
 
 add_custom_target(libloot-cpp-build
-    COMMAND cargo build
+    # Force LTO to be disabled when building the first layer of the C++ wrapper,
+    # as it may be enabled by default, and if so that leads to undefined symbols
+    # in the C++ wrapper's shared library. It's not enough to just pass -fno-lto
+    # when building libloot-cpp itself, it also needs to be passed when building
+    # the cxx crate, as otherwise there will be missing cxxbridge symbols.
+    COMMAND ${CMAKE_COMMAND} -E env --modify "CXXFLAGS=string_append: -fno-lto" --
+        cargo build
         $<$<NOT:$<CONFIG:Debug>>:--release>
         $<$<AND:$<CONFIG:Debug>,$<PLATFORM_ID:Windows>>:--config>
         $<$<AND:$<CONFIG:Debug>,$<PLATFORM_ID:Windows>>:${PROJECT_SOURCE_DIR}/.cargo/msvc-debug-config.toml>