diff --git a/src/crypto/dh.cpp b/src/crypto/dh.cpp
index cbd7dcc..ada78fa 100644
--- a/src/crypto/dh.cpp
+++ b/src/crypto/dh.cpp
@@ -69,8 +69,12 @@ namespace fc {
 
         ssl_bignum pk;
         BN_bin2bn( (unsigned char*)buf, s, pk );
-        shared_key.resize( DH_size(dh) ); 
-        DH_compute_key( (unsigned char*)&shared_key.front(), pk, dh );
+        int est_size = DH_size(dh);
+        shared_key.resize( est_size );
+        int actual_size = DH_compute_key( (unsigned char*)&shared_key.front(), pk, dh );
+        if ( actual_size < 0 ) return false;
+        if ( actual_size != est_size )
+           shared_key.resize( actual_size );
 
         return true;
    }
diff --git a/tests/crypto/dh_test.cpp b/tests/crypto/dh_test.cpp
index e972b78..e2c0941 100644
--- a/tests/crypto/dh_test.cpp
+++ b/tests/crypto/dh_test.cpp
@@ -41,14 +41,11 @@ BOOST_AUTO_TEST_CASE(dh_test)
     BOOST_CHECK( !memcmp( charlie.shared_key.data(), bob.shared_key.data(), bob.shared_key.size() ) );
     std::vector<char> bob_charlie = charlie.shared_key;
 
-    BOOST_CHECK_EQUAL( alice_bob.size(), alice_charlie.size() );
-    BOOST_CHECK( memcmp( alice_bob.data(), alice_charlie.data(), alice_bob.size() ) );
+    BOOST_CHECK( alice_bob.size() != alice_charlie.size() ||  memcmp( alice_bob.data(), alice_charlie.data(), alice_bob.size() ) );
 
-    BOOST_CHECK_EQUAL( alice_bob.size(), bob_charlie.size() );
-    BOOST_CHECK( memcmp( alice_bob.data(), bob_charlie.data(), alice_bob.size() ) );
+    BOOST_CHECK( alice_bob.size() != bob_charlie.size() || memcmp( alice_bob.data(), bob_charlie.data(), alice_bob.size() ) );
 
-    BOOST_CHECK_EQUAL( alice_charlie.size(), bob_charlie.size() );
-    BOOST_CHECK( memcmp( alice_charlie.data(), bob_charlie.data(), alice_charlie.size() ) );
+    BOOST_CHECK( alice_charlie.size() != bob_charlie.size() || memcmp( alice_charlie.data(), bob_charlie.data(), alice_charlie.size() ) );
 
     alice.p.clear(); alice.p.push_back(100); alice.p.push_back(2);
     BOOST_CHECK( !alice.validate() );