diff --git a/src/coins.cpp b/src/coins.cpp
index ef4f96fde..d79e29951 100644
--- a/src/coins.cpp
+++ b/src/coins.cpp
@@ -92,7 +92,6 @@ bool CCoinsViewCache::GetCoins(const uint256 &txid, CCoins &coins) const {
 
 CCoinsModifier CCoinsViewCache::ModifyCoins(const uint256 &txid) {
     assert(!hasModifier);
-    hasModifier = true;
     std::pair<CCoinsMap::iterator, bool> ret = cacheCoins.insert(std::make_pair(txid, CCoinsCacheEntry()));
     if (ret.second) {
         if (!base->GetCoins(txid, ret.first->second.coins)) {
@@ -233,7 +232,10 @@ double CCoinsViewCache::GetPriority(const CTransaction &tx, int nHeight) const
     return tx.ComputePriority(dResult);
 }
 
-CCoinsModifier::CCoinsModifier(CCoinsViewCache& cache_, CCoinsMap::iterator it_) : cache(cache_), it(it_) {}
+CCoinsModifier::CCoinsModifier(CCoinsViewCache& cache_, CCoinsMap::iterator it_) : cache(cache_), it(it_) {
+    assert(!cache.hasModifier);
+    cache.hasModifier = true;
+}
 
 CCoinsModifier::~CCoinsModifier()
 {
diff --git a/src/main.cpp b/src/main.cpp
index fa2b56148..ca2734b76 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1887,6 +1887,7 @@ enum FlushStateMode {
 bool static FlushStateToDisk(CValidationState &state, FlushStateMode mode) {
     LOCK(cs_main);
     static int64_t nLastWrite = 0;
+    try {
     if ((mode == FLUSH_STATE_ALWAYS) ||
         ((mode == FLUSH_STATE_PERIODIC || mode == FLUSH_STATE_IF_NEEDED) && pcoinsTip->GetCacheSize() > nCoinCacheSize) ||
         (mode == FLUSH_STATE_PERIODIC && GetTimeMicros() > nLastWrite + DATABASE_WRITE_INTERVAL * 1000000)) {
@@ -1926,6 +1927,9 @@ bool static FlushStateToDisk(CValidationState &state, FlushStateMode mode) {
         }
         nLastWrite = GetTimeMicros();
     }
+    } catch (const std::runtime_error& e) {
+        return state.Abort(std::string("System error while flushing: ") + e.what());
+    }
     return true;
 }