diff --git a/src/main.cpp b/src/main.cpp
index 59c994770..2e4c1b86d 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -33,6 +33,7 @@
 #include <boost/filesystem/fstream.hpp>
 #include <boost/math/distributions/poisson.hpp>
 #include <boost/thread.hpp>
+#include <boost/static_assert.hpp>
 
 using namespace std;
 
@@ -992,6 +993,8 @@ bool CheckTransaction(const CTransaction& tx, CValidationState &state)
                                  REJECT_INVALID, "error-computing-signature-hash");
             }
 
+            BOOST_STATIC_ASSERT(crypto_sign_PUBLICKEYBYTES == 32);
+
             if (crypto_sign_verify_detached(&tx.joinSplitSig[0],
                                             dataToBeSigned.begin(), 32,
                                             tx.joinSplitPubKey.begin()
diff --git a/src/test/sighash_tests.cpp b/src/test/sighash_tests.cpp
index 2960873c7..f8732bde2 100644
--- a/src/test/sighash_tests.cpp
+++ b/src/test/sighash_tests.cpp
@@ -82,7 +82,7 @@ uint256 static SignatureHashOld(CScript scriptCode, const CTransaction& txTo, un
     }
 
     // Blank out the joinsplit signature.
-    memset(&txTmp.joinSplitSig[0], 0, 64);
+    memset(&txTmp.joinSplitSig[0], 0, txTmp.joinSplitSig.size());
 
     // Serialize and hash
     CHashWriter ss(SER_GETHASH, 0);