diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 0000000000000000000000000000000000000000..a4460729bb4ff35bc07d7b4b5206e2aa8acbbb42
Binary files /dev/null and b/.DS_Store differ
diff --git a/README.md b/README.md
index 0a72b4fe21c8d9ae07e11f9d89e1b75d445c84b3..7274c58f261ce635c2378484a9c1d3342a09c48a 100644
--- a/README.md
+++ b/README.md
@@ -12,8 +12,6 @@ Command line and GUI tools for produce Java source code from Android Dex and Apk
 
 ![jadx-gui screenshot](http://skylot.github.io/jadx/jadx-gui.png)
 
-### add by qi
-add: check file's type by file header
 
 ### Downloads
 - [unstable](https://drone.io/github.com/skylot/jadx/files)
diff --git a/jadx-core/src/main/java/jadx/core/utils/files/FileUtils.java b/jadx-core/src/main/java/jadx/core/utils/files/FileUtils.java
index 1a4e16e777e5494f79acbda8e4a92a59cc71a0ff..09c8536c09e42cc0eacfa2bc4a255b6828e19c94 100644
--- a/jadx-core/src/main/java/jadx/core/utils/files/FileUtils.java
+++ b/jadx-core/src/main/java/jadx/core/utils/files/FileUtils.java
@@ -106,7 +106,6 @@ public class FileUtils {
 		return file;
 	}
 
-	//add by qi
 	public static String bytesToHex(byte[] bytes) {
 		char[] hexArray = "0123456789abcdef".toCharArray();
 		if (bytes == null || bytes.length <= 0) {
@@ -121,7 +120,6 @@ public class FileUtils {
 		return new String(hexChars);
 	}
 
-	//add by qi
 	public static boolean isZipfile(File file) {
 		boolean isZipfile = false;
 		InputStream is = null;
@@ -149,7 +147,6 @@ public class FileUtils {
 		return isZipfile;
 	}
 
-	//add by qi
 	public static List<String> getZipfileList(File file) {
 		List<String> filelist = new ArrayList<String>();
 		ZipFile zipFile = null;
@@ -170,7 +167,6 @@ public class FileUtils {
 		return filelist;
 	}
 
-	//add by qi
 	public static boolean isApkfile(File file) {
 		boolean isApkfile = false;
 		if (isZipfile(file)) {
@@ -182,7 +178,6 @@ public class FileUtils {
 		return isApkfile;
 	}
 
-	//add by qi
 	public static boolean isZipDexfile(File file) {
 		boolean isZipDexFile = false;
 		if (isZipfile(file)) {
diff --git a/jadx-core/src/main/java/jadx/core/utils/files/InputFile.java b/jadx-core/src/main/java/jadx/core/utils/files/InputFile.java
index c2b0fc2edb05864a1bfd893a55a5c646ecd06216..bb32bab4736dd6117764bb7c716d2632b46f021c 100644
--- a/jadx-core/src/main/java/jadx/core/utils/files/InputFile.java
+++ b/jadx-core/src/main/java/jadx/core/utils/files/InputFile.java
@@ -54,7 +54,7 @@ public class InputFile {
 			addDexFile(loadFromClassFile(file));
 			return;
 		}
-		//modifed by qi：add isApkfile() and isZipdexfile()
+
 		if (fileName.endsWith(".apk") || fileName.endsWith(".zip") || isApkfile(file) || isZipDexfile(file)) {
 			loadFromZip(".dex");
 			return;