diff --git a/make_libs.bat b/make_libs.bat
index d24107c..a4047c8 100644
--- a/make_libs.bat
+++ b/make_libs.bat
@@ -1,6 +1,6 @@
 @echo off
 set ARCH=%~1
 set PATH=%SDK_MINGW_DIR%%ARCH%\bin;%SDK_QT4_DIR%%ARCH%\bin;%SDK_CMAKE_DIR%\bin
-set Qt5_DIR=%SDK_QT5_DIR%%ARCH%
+if defined SDK_QT5_DIR set Qt5_DIR=%SDK_QT5_DIR%%ARCH%
 mkdir ..\libs_build_win%ARCH%
 cd ../libs_build_win%ARCH% && cmake_mgw -Wno-dev ../libs && make install -j8 && cd ../libs && pause