diff --git a/src/net.cpp b/src/net.cpp
index b275bdd80..97480df13 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -391,7 +391,7 @@ CNode* CConnman::ConnectNode(CAddress addrConnect, const char *pszDest, bool fCo
         uint64_t nonce = GetDeterministicRandomizer(RANDOMIZER_ID_LOCALHOSTNONCE).Write(id).Finalize();
         CNode* pnode = new CNode(id, nLocalServices, GetBestHeight(), hSocket, addrConnect, CalculateKeyedNetGroup(addrConnect), nonce, pszDest ? pszDest : "", false);
         pnode->nServicesExpected = ServiceFlags(addrConnect.nServices & nRelevantServices);
-        pnode->nTimeConnected = GetTime();
+        pnode->nTimeConnected = GetSystemTimeInSeconds();
         pnode->AddRef();
         GetNodeSignals().InitializeNode(pnode, *this);
         {
@@ -771,7 +771,7 @@ size_t CConnman::SocketSendData(CNode *pnode)
         assert(data.size() > pnode->nSendOffset);
         int nBytes = send(pnode->hSocket, reinterpret_cast<const char*>(data.data()) + pnode->nSendOffset, data.size() - pnode->nSendOffset, MSG_NOSIGNAL | MSG_DONTWAIT);
         if (nBytes > 0) {
-            pnode->nLastSend = GetTime();
+            pnode->nLastSend = GetSystemTimeInSeconds();
             pnode->nSendBytes += nBytes;
             pnode->nSendOffset += nBytes;
             nSentSize += nBytes;
@@ -1284,7 +1284,7 @@ void CConnman::ThreadSocketHandler()
             //
             // Inactivity checking
             //
-            int64_t nTime = GetTime();
+            int64_t nTime = GetSystemTimeInSeconds();
             if (nTime - pnode->nTimeConnected > 60)
             {
                 if (pnode->nLastRecv == 0 || pnode->nLastSend == 0)
@@ -2570,7 +2570,7 @@ CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn
     nLastRecv = 0;
     nSendBytes = 0;
     nRecvBytes = 0;
-    nTimeConnected = GetTime();
+    nTimeConnected = GetSystemTimeInSeconds();
     nTimeOffset = 0;
     addrName = addrNameIn == "" ? addr.ToStringIPPort() : addrNameIn;
     nVersion = 0;
diff --git a/src/qt/rpcconsole.cpp b/src/qt/rpcconsole.cpp
index 87d73b5f0..60406c205 100644
--- a/src/qt/rpcconsole.cpp
+++ b/src/qt/rpcconsole.cpp
@@ -1023,11 +1023,11 @@ void RPCConsole::updateNodeDetail(const CNodeCombinedStats *stats)
         peerAddrDetails += "<br />" + tr("via %1").arg(QString::fromStdString(stats->nodeStats.addrLocal));
     ui->peerHeading->setText(peerAddrDetails);
     ui->peerServices->setText(GUIUtil::formatServicesStr(stats->nodeStats.nServices));
-    ui->peerLastSend->setText(stats->nodeStats.nLastSend ? GUIUtil::formatDurationStr(GetTime() - stats->nodeStats.nLastSend) : tr("never"));
-    ui->peerLastRecv->setText(stats->nodeStats.nLastRecv ? GUIUtil::formatDurationStr(GetTime() - stats->nodeStats.nLastRecv) : tr("never"));
+    ui->peerLastSend->setText(stats->nodeStats.nLastSend ? GUIUtil::formatDurationStr(GetSystemTimeInSeconds() - stats->nodeStats.nLastSend) : tr("never"));
+    ui->peerLastRecv->setText(stats->nodeStats.nLastRecv ? GUIUtil::formatDurationStr(GetSystemTimeInSeconds() - stats->nodeStats.nLastRecv) : tr("never"));
     ui->peerBytesSent->setText(FormatBytes(stats->nodeStats.nSendBytes));
     ui->peerBytesRecv->setText(FormatBytes(stats->nodeStats.nRecvBytes));
-    ui->peerConnTime->setText(GUIUtil::formatDurationStr(GetTime() - stats->nodeStats.nTimeConnected));
+    ui->peerConnTime->setText(GUIUtil::formatDurationStr(GetSystemTimeInSeconds() - stats->nodeStats.nTimeConnected));
     ui->peerPingTime->setText(GUIUtil::formatPingTime(stats->nodeStats.dPingTime));
     ui->peerPingWait->setText(GUIUtil::formatPingTime(stats->nodeStats.dPingWait));
     ui->peerMinPing->setText(GUIUtil::formatPingTime(stats->nodeStats.dMinPing));
diff --git a/src/rpc/misc.cpp b/src/rpc/misc.cpp
index 54d8c3e03..480c45516 100644
--- a/src/rpc/misc.cpp
+++ b/src/rpc/misc.cpp
@@ -431,22 +431,16 @@ UniValue setmocktime(const JSONRPCRequest& request)
     if (!Params().MineBlocksOnDemand())
         throw runtime_error("setmocktime for regression testing (-regtest mode) only");
 
-    // cs_vNodes is locked and node send/receive times are updated
-    // atomically with the time change to prevent peers from being
-    // disconnected because we think we haven't communicated with them
-    // in a long time.
+    // For now, don't change mocktime if we're in the middle of validation, as
+    // this could have an effect on mempool time-based eviction, as well as
+    // IsCurrentForFeeEstimation() and IsInitialBlockDownload().
+    // TODO: figure out the right way to synchronize around mocktime, and
+    // ensure all callsites of GetTime() are accessing this safely.
     LOCK(cs_main);
 
     RPCTypeCheck(request.params, boost::assign::list_of(UniValue::VNUM));
     SetMockTime(request.params[0].get_int64());
 
-    uint64_t t = GetTime();
-    if(g_connman) {
-        g_connman->ForEachNode([t](CNode* pnode) {
-            pnode->nLastSend = pnode->nLastRecv = t;
-        });
-    }
-
     return NullUniValue;
 }
 
diff --git a/src/utiltime.cpp b/src/utiltime.cpp
index 7c5ee7726..87a25866e 100644
--- a/src/utiltime.cpp
+++ b/src/utiltime.cpp
@@ -46,6 +46,11 @@ int64_t GetTimeMicros()
     return now;
 }
 
+int64_t GetSystemTimeInSeconds()
+{
+    return GetTimeMicros()/1000000;
+}
+
 /** Return a time useful for the debug log */
 int64_t GetLogTimeMicros()
 {
diff --git a/src/utiltime.h b/src/utiltime.h
index b2807267d..05c679049 100644
--- a/src/utiltime.h
+++ b/src/utiltime.h
@@ -9,9 +9,20 @@
 #include <stdint.h>
 #include <string>
 
+/**
+ * GetTimeMicros() and GetTimeMillis() both return the system time, but in
+ * different units. GetTime() returns the sytem time in seconds, but also
+ * supports mocktime, where the time can be specified by the user, eg for
+ * testing (eg with the setmocktime rpc, or -mocktime argument).
+ *
+ * TODO: Rework these functions to be type-safe (so that we don't inadvertently
+ * compare numbers with different units, or compare a mocktime to system time).
+ */
+
 int64_t GetTime();
 int64_t GetTimeMillis();
 int64_t GetTimeMicros();
+int64_t GetSystemTimeInSeconds(); // Like GetTime(), but not mockable
 int64_t GetLogTimeMicros();
 void SetMockTime(int64_t nMockTimeIn);
 void MilliSleep(int64_t n);