diff --git a/runtime/src/main/java/org/capnproto/PackedInputStream.java b/runtime/src/main/java/org/capnproto/PackedInputStream.java
index a62c3a0..e27ce7c 100644
--- a/runtime/src/main/java/org/capnproto/PackedInputStream.java
+++ b/runtime/src/main/java/org/capnproto/PackedInputStream.java
@@ -76,7 +76,7 @@ public final class PackedInputStream implements ReadableByteChannel {
                     }
                 }
 
-                if (inBuf.remaining() ==0 && (tag == 0 || tag == (byte)0xff)) {
+                if (inBuf.remaining() == 0 && (tag == 0 || tag == (byte)0xff)) {
                     inBuf = this.inner.getReadBuffer();
                 }
             } else {
@@ -94,7 +94,7 @@ public final class PackedInputStream implements ReadableByteChannel {
                     throw new Error("Should always have non-empty buffer here.");
                 }
 
-                int runLength = inBuf.get() * 8;
+                int runLength = (0xff & (int)inBuf.get()) * 8;
 
                 if (runLength > outEnd - outPtr) {
                     throw new Error("Packed input did not end cleanly on a segment boundary");
@@ -105,8 +105,7 @@ public final class PackedInputStream implements ReadableByteChannel {
                 }
             } else if (tag == (byte)0xff) {
 
-                int runLength = inBuf.get() * 8;
-
+                int runLength = (0xff & (int)inBuf.get()) * 8;
 
                 if (inBuf.remaining() >= runLength) {
                     //# Fast path.
diff --git a/runtime/src/test/scala/org/capnproto/SerializePackedSuite.scala b/runtime/src/test/scala/org/capnproto/SerializePackedSuite.scala
index d2078bb..65247ba 100644
--- a/runtime/src/test/scala/org/capnproto/SerializePackedSuite.scala
+++ b/runtime/src/test/scala/org/capnproto/SerializePackedSuite.scala
@@ -51,8 +51,6 @@ class SerializePackedSuite extends FunSuite {
 
       (bytes) should equal (unpacked)
     }
-
-
   }
 
   test("SimplePacking") {
@@ -80,5 +78,12 @@ class SerializePackedSuite extends FunSuite {
 
     expectPacksTo(Array(0,0,0,0,2,0,0,0, 0,0,0,0,0,0,1,0, 0,0,0,0,0,0,0,0),
                   Array(0x10,2, 0x40,1, 0,0))
+
+    expectPacksTo(Array.tabulate[Byte](8 * 200)((n) => 0),
+                  Array(0, 199.toByte))
+
+    expectPacksTo(Array.tabulate[Byte](8 * 200)((n) => 1),
+                  Array.concat(Array(0xff.toByte, 1,1,1,1,1,1,1,1, 199.toByte),
+                               Array.tabulate[Byte](8 * 199)((n) => 1)))
   }
 }