diff --git a/core/src/com/riiablo/io/nio/BitInput.java b/core/src/com/riiablo/io/nio/BitInput.java
index e3c2bd49..b3540b4b 100644
--- a/core/src/com/riiablo/io/nio/BitInput.java
+++ b/core/src/com/riiablo/io/nio/BitInput.java
@@ -22,10 +22,9 @@ public class BitInput {
     }
   }
 
-  final ByteInput byteInput;
-  final long numBits;
-  long bitsRead;
-
+  private final ByteInput byteInput;
+  private final long numBits;
+  private long bitsRead;
   private int bitsCached;
   private long cache;
 
@@ -48,6 +47,10 @@ public class BitInput {
     this.numBits = numBits;
   }
 
+  ByteInput byteInput() {
+    return byteInput;
+  }
+
   public int bytesRead() {
     return byteInput.bytesRead();
   }
@@ -136,7 +139,7 @@ public class BitInput {
     // length should include the last byte that bits belong (round to ceil)
     final long numBytes = (numBits - bitsCached + Byte.SIZE - 1) / Byte.SIZE;
     final ByteInput byteInput = this.byteInput.readSlice(numBytes);
-    return byteInput.bitInput = new BitInput(byteInput, bitsCached, cache, numBits);
+    return byteInput.bitInput(new BitInput(byteInput, bitsCached, cache, numBits));
   }
 
   /**
diff --git a/core/src/com/riiablo/io/nio/ByteInput.java b/core/src/com/riiablo/io/nio/ByteInput.java
index d33c9907..30b22121 100644
--- a/core/src/com/riiablo/io/nio/ByteInput.java
+++ b/core/src/com/riiablo/io/nio/ByteInput.java
@@ -17,13 +17,19 @@ public class ByteInput {
     return bytes == null ? emptyByteInput() : new ByteInput(Unpooled.wrappedBuffer(bytes));
   }
 
-  final ByteBuf buffer;
-  BitInput bitInput;
+  private final ByteBuf buffer;
+  private BitInput bitInput;
 
   ByteInput(ByteBuf buffer) {
     this.buffer = buffer;
   }
 
+  BitInput bitInput(BitInput bitInput) {
+    assert this.bitInput == null : "this.bitInput(" + this.bitInput + ") != null";
+    assert bitInput.byteInput() == this : "bitInput.byteInput()(" + bitInput.byteInput() + ") != this(" + this + ")";
+    return this.bitInput = bitInput;
+  }
+
   public int bytesRead() {
     return buffer.readerIndex();
   }