diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
index 11e20a23f..beeba7404 100644
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -952,12 +952,12 @@ UniValue getblocktemplate(const JSONRPCRequest& request)
     std::string kevaBlockData = HexStr(stream.begin(), stream.end());
     cryptonote::tx_extra_keva_block extra_keva_block;
     extra_keva_block.keva_block = kevaBlockData;
-    if (cryptonote::append_keva_block_to_extra(cn_block.miner_tx.extra, extra_keva_block)) {
+    if (!cryptonote::append_keva_block_to_extra(cn_block.miner_tx.extra, extra_keva_block)) {
         throw JSONRPCError(RPC_INTERNAL_ERROR, "Internal error: failed to add block");
     }
 
     UniValue result(UniValue::VOBJ);
-    const double difficulty = ConvertNBitsToDiff(pblock->nBits);
+    const uint64_t difficulty = ConvertNBitsToDiff(pblock->nBits);
     result.push_back(Pair("blocktemplate_blob", pblock->hashPrevBlock.GetHex()));
     result.push_back(Pair("difficulty", (double)difficulty));
     result.push_back(Pair("height", (uint64_t)height));
diff --git a/src/util.cpp b/src/util.cpp
index 266265084..568d39cdc 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -962,7 +962,7 @@ int64_t GetStartupTime()
     return nStartupTime;
 }
 
-double ConvertNBitsToDiff(uint32_t nBits)
+uint64_t ConvertNBitsToDiff(uint32_t nBits)
 {
     int nShift = (nBits >> 24) & 0xff;
 
@@ -981,5 +981,5 @@ double ConvertNBitsToDiff(uint32_t nBits)
         nShift--;
     }
 
-    return dDiff;
+    return (uint64_t)round(dDiff);
 }
\ No newline at end of file
diff --git a/src/util.h b/src/util.h
index d85fcd698..f9036f702 100644
--- a/src/util.h
+++ b/src/util.h
@@ -349,6 +349,6 @@ std::unique_ptr<T> MakeUnique(Args&&... args)
     return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
 }
 
-double ConvertNBitsToDiff(uint32_t nBits);
+uint64_t ConvertNBitsToDiff(uint32_t nBits);
 
 #endif // BITCOIN_UTIL_H