diff --git a/include/llvm/Bitcode/Deserialize.h b/include/llvm/Bitcode/Deserialize.h
index 46b111f8929..ef25da71409 100644
--- a/include/llvm/Bitcode/Deserialize.h
+++ b/include/llvm/Bitcode/Deserialize.h
@@ -141,8 +141,8 @@ public:
   SerializedPtrID ReadPtrID() { return (SerializedPtrID) ReadInt(); }
 
   SerializedPtrID ReadDiffPtrID(SerializedPtrID& PrevID) {
-    unsigned x = ReadInt();    
-    return (SerializedPtrID) (x ? (PrevID+x) : 0);
+    bool x = ReadBool();    
+    return (SerializedPtrID) (x ? (PrevID+1) : 0);
   }
   
   
diff --git a/include/llvm/Bitcode/Serialize.h b/include/llvm/Bitcode/Serialize.h
index 8db377946c4..9430bb10a42 100644
--- a/include/llvm/Bitcode/Serialize.h
+++ b/include/llvm/Bitcode/Serialize.h
@@ -57,10 +57,11 @@ public:
     SerializedPtrID ptr_id = getPtrId(ptr);
 
     if (ptr_id == 0)
-      EmitInt(0);
+      EmitBool(false);
     else {
       assert (ptr_id > PrevID);
-      EmitInt(ptr_id-PrevID);
+      assert (PrevID == 0 || ptr_id - PrevID == 1);
+      EmitBool(true);
     }
     
     return ptr_id;