diff --git a/nimbus/vm/interpreter/gas_costs.nim b/nimbus/vm/interpreter/gas_costs.nim
index ebe06a560..2185440e0 100644
--- a/nimbus/vm/interpreter/gas_costs.nim
+++ b/nimbus/vm/interpreter/gas_costs.nim
@@ -273,9 +273,9 @@ template gasCosts(fork: Fork, prefix, ResultGasCostsName: untyped) =
 
       if gasParams.s_originalValue == value:
         if gasParams.s_originalValue.isZero: # reset to original inexistent slot (2.2.2.1)
-          result.gasRefund = InitRefundEIP2200
+          result.gasRefund += InitRefundEIP2200
         else: # reset to original existing slot (2.2.2.2)
-          result.gasRefund = CleanRefundEIP2200
+          result.gasRefund += CleanRefundEIP2200
 
       result.gasCost = DirtyGasEIP2200 # dirty update (2.2)
 
diff --git a/nimbus/vm/interpreter/opcodes_impl.nim b/nimbus/vm/interpreter/opcodes_impl.nim
index 9b135f5d8..91d5ab3a8 100644
--- a/nimbus/vm/interpreter/opcodes_impl.nim
+++ b/nimbus/vm/interpreter/opcodes_impl.nim
@@ -951,7 +951,7 @@ op sstoreEIP2200, inline = false, slot, value:
 
   computation.gasMeter.consumeGas(gasCost, &"SSTORE EIP2200: {computation.msg.storageAddress}[{slot}] -> {value} ({currentValue})")
 
-  if gasRefund > 0:
+  if gasRefund != 0:
     computation.gasMeter.refundGas(gasRefund)
 
   computation.vmState.mutateStateDB: