diff --git a/utils/misc/variables.msvc b/utils/misc/variables.msvc
index 9b184111abdfcf86affa53cdf0c57cffbf3a6ed7..39a42d705fd481512062a1c7a2f81fca99da15cf 100644
--- a/utils/misc/variables.msvc
+++ b/utils/misc/variables.msvc
@@ -42,7 +42,11 @@ GSL_PREFIX="E:/src/gsl-1.8"
 FLTK_PREFIX="E:/src/fltk-1.1.9"
 
 # If you selected ENABLE_OCC, specify where OpenCASCADE is installed
-OCC_PREFIX="E:/src/OpenCASCADE6.3.0/ros"
+ifneq ($(CASROOT),)
+      OCC_PREFIX="${CASROOT}"
+else
+	OCC_PREFIX="E:/src/OpenCASCADE6.3.0/ros"
+endif
 
 # If you selected ENABLE_MED, specify where MED and HDF5 are installed
 MED_PREFIX="E:/src/med-2.3.4"