diff --git a/src/net_processing.h b/src/net_processing.h
index 1f1db27b1..b1b64670c 100644
--- a/src/net_processing.h
+++ b/src/net_processing.h
@@ -10,6 +10,7 @@
 #include <net.h>
 #include <validationinterface.h>
 #include <consensus/params.h>
+#include <validation.h>
 
 /** Default for -maxorphantx, maximum number of orphan transactions kept in memory */
 static const unsigned int DEFAULT_MAX_ORPHAN_TRANSACTIONS = 100;
diff --git a/src/validation.cpp b/src/validation.cpp
index 18bc7259b..66648ac80 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -3394,7 +3394,7 @@ static bool ContextualCheckBlock(const CBlock& block, CValidationState& state, c
         return state.DoS(100, false, REJECT_INVALID, "bad-blk-weight", false, strprintf("%s : weight limit failed", __func__));
     }
 
-    if (block.GetBlockTime() <= pindexPrev->GetMedianTimePast() || block.GetBlockTime() + GetMaxClockDrift(nHeight) < pindexPrev->GetBlockTime())
+    if (nHeight > 0 && (block.GetBlockTime() <= pindexPrev->GetMedianTimePast() || block.GetBlockTime() + GetMaxClockDrift(nHeight) < pindexPrev->GetBlockTime()))
     {	        
         state.DoS(100, false, REJECT_INVALID, "bad-blk-time", false, strprintf("%s : blocks timestamp is too early", __func__));
     }