diff --git a/src/main.cpp b/src/main.cpp
index ad5a7b0f1..723b8d75e 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1319,7 +1319,9 @@ bool CTransaction::CheckInputs(CCoinsViewCache &inputs, enum CheckSig_mode csmod
         if (!HaveInputs(inputs))
             return error("CheckInputs() : %s inputs unavailable", GetHash().ToString().substr(0,10).c_str());
 
-        CBlockIndex *pindexBlock = inputs.GetBestBlock();
+        // While checking, GetBestBlock() refers to the parent block.
+        // This is also true for mempool checks.
+        int nSpendHeight = inputs.GetBestBlock()->nHeight + 1; 
         int64 nValueIn = 0;
         int64 nFees = 0;
         for (unsigned int i = 0; i < vin.size(); i++)
@@ -1329,8 +1331,8 @@ bool CTransaction::CheckInputs(CCoinsViewCache &inputs, enum CheckSig_mode csmod
 
             // If prev is coinbase, check that it's matured
             if (coins.IsCoinBase()) {
-                if (pindexBlock->nHeight - coins.nHeight < COINBASE_MATURITY)
-                    return error("CheckInputs() : tried to spend coinbase at depth %d", pindexBlock->nHeight - coins.nHeight);
+                if (nSpendHeight - coins.nHeight < COINBASE_MATURITY)
+                    return error("CheckInputs() : tried to spend coinbase at depth %d", nSpendHeight - coins.nHeight);
             }
 
             // Check for negative or overflow input values