diff --git a/init_hdl.sh b/init_hdl.sh
index 6c72df6cdd5cf80d24b4e79f02f0182de24133d6..ab43b537eb6564849715def3ce641e974d5c7636 100644
--- a/init_hdl.sh
+++ b/init_hdl.sh
@@ -54,6 +54,16 @@ if [[ ! -d "${HDL_BUILD_DIR}" ]]; then
     echo "${HDL_BUILD_DIR}"
     mkdir "${HDL_BUILD_DIR}"
 fi
+
+# set modelsim_altera_libs dir
+export MODELSIM_ALTERA_LIBS_DIR=${HDL_BUILD_DIR}/quartus
+if [[ ! -d "${MODELSIM_ALTERA_LIBS_DIR}" ]]; then
+    echo "make modelsim_altera_libs dir"
+    echo "${MODELSIM_ALTERA_LIBS_DIR}"
+    mkdir "${MODELSIM_ALTERA_LIBS_DIR}"
+    echo "This dir is also used as modelsim_altera_libs dir" > ${MODELSIM_ALTERA_LIBS_DIR}/readme.txt
+fi
+
 # modelsim uses this sim dir for testing
 export HDL_IOFILE_SIM_DIR=${HDL_BUILD_DIR}/sim
 if [[ ! -d "${HDL_IOFILE_SIM_DIR}" ]]; then