diff --git a/src/txmempool.cpp b/src/txmempool.cpp
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -22,6 +22,8 @@
 
 #include <boost/range/adaptor/reversed.hpp>
 
+#include <algorithm>
+
 CTxMemPoolEntry::CTxMemPoolEntry(const CTransactionRef &_tx, const Amount _nFee,
                                  int64_t _nTime, double _entryPriority,
                                  unsigned int _entryHeight,
@@ -964,13 +966,33 @@
 
 CFeeRate CTxMemPool::estimateFee(int nBlocks) const {
     LOCK(cs);
-    return minerPolicyEstimator->estimateFee(nBlocks);
+
+    uint64_t maxMempoolSize =
+        gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000;
+    // minerPolicy uses recent blocks to figure out a reasonable fee.  This may
+    // disagree
+    // with the rollingMinimumFeerate under certain scenarios where the blocks
+    // include low fee
+    // transactions, but the mempool is being spammed.
+    // Therefore, use the maximum of the two values.
+    return std::max(minerPolicyEstimator->estimateFee(nBlocks),
+                    GetMinFee(maxMempoolSize));
 }
 CFeeRate CTxMemPool::estimateSmartFee(int nBlocks,
                                       int *answerFoundAtBlocks) const {
     LOCK(cs);
-    return minerPolicyEstimator->estimateSmartFee(nBlocks, answerFoundAtBlocks,
-                                                  *this);
+    uint64_t maxMempoolSize =
+        gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000;
+
+    // minerPolicy uses recent blocks to figure out a reasonable fee.  This may
+    // disagree
+    // with the rollingMinimumFeerate under certain scenarios where the blocks
+    // include low fee
+    // transactions, but the mempool is being spammed.
+    // Therefore, use the maximum of the two values.
+    return std::max(minerPolicyEstimator->estimateSmartFee(
+                        nBlocks, answerFoundAtBlocks, *this),
+                    GetMinFee(maxMempoolSize));
 }
 
 bool CTxMemPool::WriteFeeEstimates(CAutoFile &fileout) const {