diff --git a/prepare_sources.sh b/prepare_sources.sh
index 3fa41adb9..e7486f0a7 100755
--- a/prepare_sources.sh
+++ b/prepare_sources.sh
@@ -4,9 +4,14 @@ topdir=`pwd`
 
 if test -z "$1" ; then
 	ndk_build_path=`which ndk-build`
+	if test "$?" != "0" ; then
+		echo "ndk-build not found in path. Please specify path to android NDK as first argument of $0."
+		exit 127
+	fi
 	NDK_PATH=`dirname $ndk_build_path`
 	if test -z "NDK_PATH" ; then
-		echo "Path to Android NDK not set, please specify it as first argument of $0"
+		echo "Path to Android NDK not set, please specify it as first argument of $0."
+		exit 127
 	fi
 else
 	NDK_PATH=$1