diff --git a/CMakeLists.txt b/CMakeLists.txt
index d519c9d6e6..68b8bb0d23 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -177,7 +177,17 @@ if(MSVC)
     OPTION(FREECAD_RELEASE_SEH "Enable Structured Exception Handling for Release version." ON)
     OPTION(FREECAD_LIBPACK_USE "Use the LibPack to Build FreeCAD (only Win32 so far)." ON)
     OPTION(FREECAD_LIBPACK_USEPYSIDE "Use PySide in LibPack rather to PyQt and Swig." ON)
-    set(FREECAD_LIBPACK_DIR ${CMAKE_SOURCE_DIR} CACHE PATH  "Directory of the FreeCAD LibPack")
+    IF(DEFINED ENV{FREECAD_LIBPACK_DIR})
+      set(FREECAD_LIBPACK_DIR $ENV{FREECAD_LIBPACK_DIR} CACHE PATH  "Directory of the FreeCAD LibPack")
+      MESSAGE(STATUS "Found libpack env variable: ${FREECAD_LIBPACK_DIR}")
+      IF(EXISTS ${FREECAD_LIBPACK_DIR}/lib/Qt5Core.lib)
+        OPTION(BUILD_QT5 "Build with Qt5." ON)
+      ELSE()
+        OPTION(BUILD_QT5 "Build with Qt5." OFF)
+      ENDIF()
+    ELSE()
+        set(FREECAD_LIBPACK_DIR ${CMAKE_SOURCE_DIR} CACHE PATH  "Directory of the FreeCAD LibPack")
+    ENDIF()
     OPTION(BUILD_USE_PCH "Activate precompiled headers where it's used." ON)
 else(MSVC)
     OPTION(FREECAD_LIBPACK_USE "Use the LibPack to Build FreeCAD (only Win32 so far)." OFF)