diff --git a/AccountState.h b/AccountState.h
index cc811caeb5..4090465542 100644
--- a/AccountState.h
+++ b/AccountState.h
@@ -2,11 +2,15 @@
 #define __ACCOUNTSTATE__
 
 // An account's state in one or more accepted ledgers
+#include "uint256.h"
 
 class AccountState
 {
+public:
+    typedef boost::shared_ptr<AccountState> pointer;
+
 private:
-    int160 mAccountID;
+    uint160 mAccountID;
     uint64 mBalance;
     uint32 mAccountSeq, mFirstValidLedger, mLastValidLedger;