diff --git a/flash/factory.common b/flash/factory.common
index 9131a7d209d506f8a6eb45c4bf8ec3da5377ff17..7067a33d6bb53ba43c31c3cc9a33b1d31c261665 100755
--- a/flash/factory.common
+++ b/flash/factory.common
@@ -30,9 +30,10 @@ check_unlock_status() {
       echo "Please follow the instructions to unlock the bootloader!"
       PHONE_IS_READY=false
     fi
-    if ("${FASTBOOT_BIN}" oem device-info 2>&1 | grep -q "critical unlocked: false"); then
-      echo "Error: Critical partitions are still locked."
-      echo "Did you execute 'fastboot flashing unlock_critical'?"
+    DEVICE_INFO_OUTPUT=$("${FASTBOOT_BIN}" oem device-info 2>&1)
+    if [[ $DEVICE_INFO_OUTPUT != *"Device critical unlocked: true"* ]]; then
+      echo "Error: Critical partitions are not unlocked."
+      echo "Please execute 'fastboot flashing unlock_critical' first!"
       PHONE_IS_READY=false
     fi
   fi