diff --git a/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/DexBuffer.java b/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/DexBuffer.java
index f6ce5d59..0ffdee56 100644
--- a/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/DexBuffer.java
+++ b/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/DexBuffer.java
@@ -33,13 +33,14 @@ package org.jf.dexlib2.dexbacked;
 
 import org.jf.util.ExceptionWithContext;
 
+import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
 public class DexBuffer {
     // TODO: consider using a direct ByteBuffer instead
-    protected final byte[] buf;
+    @Nonnull protected final byte[] buf;
 
-    public DexBuffer(byte[] buf) {
+    public DexBuffer(@Nonnull byte[] buf) {
         this.buf = buf;
     }
 
diff --git a/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/DexReader.java b/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/DexReader.java
index e77213ff..48f583d0 100644
--- a/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/DexReader.java
+++ b/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/DexReader.java
@@ -227,7 +227,6 @@ public class DexReader {
     public int readShort(int offset) { return dexBuf.readShort(offset); }
     public int readByte(int offset) { return dexBuf.readByte(offset); }
 
-
     public int readSizedInt(int bytes) {
         int o = offset;
         byte[] buf = dexBuf.buf;