diff --git a/README.md b/README.md
index b4b40bd..b859309 100644
--- a/README.md
+++ b/README.md
@@ -37,7 +37,7 @@ The following environment variables are supported:
    but you should use something else for a customized version.  Export files
    in stages may add suffixes to `IMG_NAME`.
 
-* `USE_QCOW2`(Default: `1` )
+* `USE_QCOW2` **EXPERIMENTAL** (Default: `0` )
 
     Instead of using traditional way of building the rootfs of every stage in
     single subdirectories and copying over the previous one to the next one,
diff --git a/build.sh b/build.sh
index 423d62e..bcfdeb6 100755
--- a/build.sh
+++ b/build.sh
@@ -99,7 +99,7 @@ run_stage(){
 	STAGE_WORK_DIR="${WORK_DIR}/${STAGE}"
 	ROOTFS_DIR="${STAGE_WORK_DIR}"/rootfs
 
-	if [ "${USE_QCOW2}" = "1" ]; then 
+	if [ "${USE_QCOW2}" = "1" ]; then
 		if [ ! -f SKIP ]; then
 			load_qimage
 		fi
@@ -109,7 +109,7 @@ run_stage(){
 			unmount "${WORK_DIR}/${STAGE}"
 		fi
 	fi
-	
+
 	if [ ! -f SKIP_IMAGES ]; then
 		if [ -f "${STAGE_DIR}/EXPORT_IMAGE" ]; then
 			EXPORT_DIRS="${EXPORT_DIRS} ${STAGE_DIR}"
@@ -253,7 +253,7 @@ source "${SCRIPT_DIR}/common"
 source "${SCRIPT_DIR}/dependencies_check"
 
 export NO_PRERUN_QCOW2="${NO_PRERUN_QCOW2:-1}"
-export USE_QCOW2="${USE_QCOW2:-1}"
+export USE_QCOW2="${USE_QCOW2:-0}"
 export BASE_QCOW2_SIZE=${BASE_QCOW2_SIZE:-12G}
 source "${SCRIPT_DIR}/qcow2_handling"
 if [ "${USE_QCOW2}" = "1" ]; then