diff -uNr a/bitcoin/src/bitcoinrpc.cpp b/bitcoin/src/bitcoinrpc.cpp
--- a/bitcoin/src/bitcoinrpc.cpp d5edc4c67519900497dc7f576070808e67519d2921981c63fc5c80d14dc2f8040544cd1c79ac202194dfa07fafd6245ebed5bab25b86cf5efb9e901659d0d8b5
+++ b/bitcoin/src/bitcoinrpc.cpp cd1dcc5febddd45408b193d0b875d8951eed8dc29d342ae5e57330b4ea2b55d959fab19e634696234c698feb4fa79a5702278e83b3896389c425ada5e935cc34
@@ -1784,7 +1784,7 @@
 
 Value dumpblock(const Array& params, bool fHelp)
 {
-    if (fHelp || params.size() < 1 || params.size() > 2)
+    if (fHelp || params.size() != 2)
         throw runtime_error(
             "dumpblock <height> <filename>\n"
             "Emit the block at <height> to <filename>.");