1 files changed, 10 insertions, 9 deletions
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index d6989add89..97d6dc700c 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -1893,19 +1893,20 @@ UniValue listsinceblock(const JSONRPCRequest& request)
     int target_confirms = 1;
     isminefilter filter = ISMINE_SPENDABLE;
 
-    if (!request.params[0].isNull()) {
+    if (!request.params[0].isNull() && !request.params[0].get_str().empty()) {
         uint256 blockId;
 
         blockId.SetHex(request.params[0].get_str());
         BlockMap::iterator it = mapBlockIndex.find(blockId);
-        if (it != mapBlockIndex.end()) {
-            paltindex = pindex = it->second;
-            if (chainActive[pindex->nHeight] != pindex) {
-                // the block being asked for is a part of a deactivated chain;
-                // we don't want to depend on its perceived height in the block
-                // chain, we want to instead use the last common ancestor
-                pindex = chainActive.FindFork(pindex);
-            }
+        if (it == mapBlockIndex.end()) {
+            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
+        }
+        paltindex = pindex = it->second;
+        if (chainActive[pindex->nHeight] != pindex) {
+            // the block being asked for is a part of a deactivated chain;
+            // we don't want to depend on its perceived height in the block
+            // chain, we want to instead use the last common ancestor
+            pindex = chainActive.FindFork(pindex);
         }
     }