diff --git a/scripts/util_functions.sh b/scripts/util_functions.sh
index 2550de045..0b001c8e2 100644
--- a/scripts/util_functions.sh
+++ b/scripts/util_functions.sh
@@ -438,8 +438,10 @@ install_magisk() {
     BOOTIMAGE=boot.img
   fi
 
-  eval $BOOTSIGNER -verify < $BOOTIMAGE && BOOTSIGNED=true
-  $BOOTSIGNED && ui_print "- Boot image is signed with AVB 1.0"
+  if [ $API -ge 21 ]; then
+    eval $BOOTSIGNER -verify < $BOOTIMAGE && BOOTSIGNED=true
+    $BOOTSIGNED && ui_print "- Boot image is signed with AVB 1.0"
+  fi
 
   $IS64BIT && mv -f magiskinit64 magiskinit 2>/dev/null || rm -f magiskinit64