diff --git a/contrib/devtools/check-doc.py b/contrib/devtools/check-doc.py
index 8c73cf1e8..fa1e13758 100755
--- a/contrib/devtools/check-doc.py
+++ b/contrib/devtools/check-doc.py
@@ -21,7 +21,7 @@ CMD_GREP_DOCS = r"egrep -r -I 'HelpMessageOpt\(\"\-[^\"=]+?(=|\")' %s" % (CMD_RO
 REGEX_ARG = re.compile(r'(?:map(?:Multi)?Args(?:\.count\(|\[)|Get(?:Bool)?Arg\()\"(\-[^\"]+?)\"')
 REGEX_DOC = re.compile(r'HelpMessageOpt\(\"(\-[^\"=]+?)(?:=|\")')
 # list unsupported, deprecated and duplicate args as they need no documentation
-SET_DOC_OPTIONAL = set(['-rpcssl', '-benchmark', '-h', '-help', '-socks', '-tor', '-debugnet', '-whitelistalwaysrelay'])
+SET_DOC_OPTIONAL = set(['-rpcssl', '-benchmark', '-h', '-help', '-socks', '-tor', '-debugnet', '-whitelistalwaysrelay', '-blockminsize'])
 
 def main():
   used = check_output(CMD_GREP_ARGS, shell=True)
diff --git a/src/init.cpp b/src/init.cpp
index 137376f48..40e8b0a91 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -889,6 +889,9 @@ bool AppInit2(Config& config, boost::thread_group& threadGroup, CScheduler& sche
     if (GetBoolArg("-whitelistalwaysrelay", false))
         InitWarning(_("Unsupported argument -whitelistalwaysrelay ignored, use -whitelistrelay and/or -whitelistforcerelay."));
 
+    if (mapArgs.count("-blockminsize"))
+        InitWarning("Unsupported argument -blockminsize ignored.");
+
     // Checkmempool and checkblockindex default to true in regtest mode
     int ratio = std::min<int>(std::max<int>(GetArg("-checkmempool", chainparams.DefaultConsistencyChecks() ? 1 : 0), 0), 1000000);
     if (ratio != 0) {