diff --git a/build/core/build-local.mk b/build/core/build-local.mk
index b68eb98..7ed3001 100644
--- a/build/core/build-local.mk
+++ b/build/core/build-local.mk
@@ -89,13 +89,3 @@
 
 # Build it
 include $(BUILD_SYSTEM)/build-all.mk
-
-
-#
-# Transfer the control to NDK
-#
-ifndef NDK_ROOT
-  $(info Android GDK: You must specify NDK_ROOT.)
-  $(error Abort.)
-endif
-include $(NDK_ROOT)/build/core/build-local.mk
diff --git a/gdk-build b/gdk-build
index 03e4018..bb6520a 100755
--- a/gdk-build
+++ b/gdk-build
@@ -37,6 +37,22 @@
 #    cd ndk
 #    ./ndk-build -C <project-path>
 #
+
+if [ $# -lt 1 ]; then
+  echo "Usage: $0 --ndk-root=<where> ..."
+  echo
+  exit 1
+fi
+
+if [ `echo $1 | awk -F '--' '{print $1}' | awk -F '=' '{print $1}' != "ndk-root"` ]; then
+  echo "Usage: $0 --ndk-root=<where> ..."
+  echo
+  exit 1
+fi
+
+NDK_ROOT=`echo $1 | awk -F '--' '{print $2}' | awk -F '=' '{print $2}'`
+shift 1
+
 PROGDIR=`dirname $0`
 PROGDIR=`cd $PROGDIR && pwd`
 
@@ -87,3 +103,6 @@
 fi
 
 $GNUMAKE -f $PROGDIR/build/core/build-local.mk "$@"
+
+# Transfer the control power to NDK
+$GNUMAKE -f $NDK_ROOT/build/core/build-local.mk "$@"