diff --git a/src/coins.h b/src/coins.h
--- a/src/coins.h
+++ b/src/coins.h
@@ -232,9 +232,14 @@
     bool HaveCoinInCache(const COutPoint &outpoint) const;
 
     /**
-     * Return a reference to a Coin in the cache, or a pruned one if not found.
-     * This is more efficient than GetCoin. Modifications to other cache entries
-     * are allowed while accessing the returned pointer.
+     * Return a reference to Coin in the cache, or a pruned one if not found.
+     * This is more efficient than GetCoin.
+     *
+     * Generally, do not hold the reference returned for more than a short
+     * scope. While the current implementation allows for modifications to the
+     * contents of the cache while holding the reference, this behavior should
+     * not be relied on! To be safe, best to not hold the returned reference
+     * through any other calls to this cache.
      */
     const Coin &AccessCoin(const COutPoint &output) const;
 
diff --git a/src/txmempool.cpp b/src/txmempool.cpp
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -1201,9 +1201,7 @@
                     if (exists(txin.prevout.GetTxId())) {
                         continue;
                     }
-                    if (!mapNextTx.count(txin.prevout)) {
-                        pvNoSpendsRemaining->push_back(txin.prevout);
-                    }
+                    pvNoSpendsRemaining->push_back(txin.prevout);
                 }
             }
         }