diff --git a/src/chain.h b/src/chain.h
--- a/src/chain.h
+++ b/src/chain.h
@@ -130,11 +130,7 @@
         nVersion = block.nVersion;
         hashMerkleRoot = block.hashMerkleRoot;
         nTime = block.nTime;
-        // Default to block time if nTimeReceived is never set, which
-        // in effect assumes that this block is honestly mined.
-        // Note that nTimeReceived isn't written to disk, so blocks read from
-        // disk will be assumed to be honestly mined.
-        nTimeReceived = block.nTime;
+        nTimeReceived = 0;
         nBits = block.nBits;
         nNonce = block.nNonce;
     }
@@ -176,7 +172,12 @@
 
     int64_t GetBlockTimeMax() const { return int64_t(nTimeMax); }
 
-    int64_t GetHeaderReceivedTime() const { return nTimeReceived; }
+    int64_t GetHeaderReceivedTime(bool guessUnknownTime = true) const {
+        if (guessUnknownTime && nTimeReceived == 0) {
+            return GetBlockTime();
+        }
+        return nTimeReceived;
+    }
 
     int64_t GetReceivedTimeDiff() const {
         return GetHeaderReceivedTime() - GetBlockTime();
diff --git a/src/test/blockindex_tests.cpp b/src/test/blockindex_tests.cpp
--- a/src/test/blockindex_tests.cpp
+++ b/src/test/blockindex_tests.cpp
@@ -117,8 +117,14 @@
 
     CBlockIndex index = CBlockIndex(header);
 
-    // nTimeReceived defaults to block time
-    BOOST_CHECK(index.nTimeReceived == expectedBlockTime);
+    // nTimeReceived defaults to 0
+    BOOST_CHECK_EQUAL(index.nTimeReceived, 0);
+
+    // If guessUnkwnowTime is true/unset and nTimeReceived is 0,
+    // GetHeaderReceivedTime() returns nTime as an approximation
+    BOOST_CHECK_EQUAL(index.GetHeaderReceivedTime(), index.nTime);
+    // If guessUnkwnowTime is false it always returns nTimeReceived
+    BOOST_CHECK_EQUAL(index.GetHeaderReceivedTime(false), index.nTimeReceived);
 
     // nTimeReceived can be updated to the actual received time, which may
     // be before or after the miner's time.
@@ -126,10 +132,10 @@
          // Make sure that receivedTime is tested beyond 32-bit values.
          receivedTime <= expectedBlockTime + 10; receivedTime++) {
         index.nTimeReceived = receivedTime;
-        BOOST_CHECK(index.GetBlockTime() == expectedBlockTime);
-        BOOST_CHECK(index.GetHeaderReceivedTime() == receivedTime);
-        BOOST_CHECK(index.GetReceivedTimeDiff() ==
-                    receivedTime - expectedBlockTime);
+        BOOST_CHECK_EQUAL(index.GetBlockTime(), expectedBlockTime);
+        BOOST_CHECK_EQUAL(index.GetHeaderReceivedTime(), receivedTime);
+        BOOST_CHECK_EQUAL(index.GetReceivedTimeDiff(),
+                          receivedTime - expectedBlockTime);
     }
 }