diff --git a/src/qt/test/rpcnestedtests.cpp b/src/qt/test/rpcnestedtests.cpp
--- a/src/qt/test/rpcnestedtests.cpp
+++ b/src/qt/test/rpcnestedtests.cpp
@@ -26,7 +26,7 @@
             {"arg2", RPCArg::Type::STR, RPCArg::Optional::OMITTED, ""},
             {"arg3", RPCArg::Type::STR, RPCArg::Optional::OMITTED, ""},
         },
-        {},
+        RPCResult{RPCResult::Type::ANY, "", ""},
         RPCExamples{""},
         [](const RPCHelpMan &self, const Config &config,
            const JSONRPCRequest &request) -> UniValue {
diff --git a/src/rpc/abc.cpp b/src/rpc/abc.cpp
--- a/src/rpc/abc.cpp
+++ b/src/rpc/abc.cpp
@@ -18,7 +18,13 @@
         "getexcessiveblock",
         "Return the excessive block size.",
         {},
-        RPCResult{RPCResult::Type::NUM, "", "excessive block size in bytes"},
+        RPCResult{RPCResult::Type::OBJ,
+                  "",
+                  "",
+                  {
+                      RPCResult{RPCResult::Type::NUM, "",
+                                "excessive block size in bytes"},
+                  }},
         RPCExamples{HelpExampleCli("getexcessiveblock", "") +
                     HelpExampleRpc("getexcessiveblock", "")},
         [&](const RPCHelpMan &self, const Config &config,
diff --git a/src/rpc/misc.cpp b/src/rpc/misc.cpp
--- a/src/rpc/misc.cpp
+++ b/src/rpc/misc.cpp
@@ -768,7 +768,7 @@
             {"arg9", RPCArg::Type::STR, RPCArg::Optional::OMITTED_NAMED_ARG,
              ""},
         },
-        RPCResult{RPCResult::Type::NONE, "", "Returns whatever was passed in"},
+        RPCResult{RPCResult::Type::ANY, "", "Returns whatever was passed in"},
         RPCExamples{""},
         [&](const RPCHelpMan &self, const Config &config,
             const JSONRPCRequest &request) -> UniValue {
diff --git a/src/rpc/server.cpp b/src/rpc/server.cpp
--- a/src/rpc/server.cpp
+++ b/src/rpc/server.cpp
@@ -182,7 +182,10 @@
             {"command", RPCArg::Type::STR, /* default */ "all commands",
              "The command to get help on"},
         },
-        RPCResult{RPCResult::Type::STR, "", "The help text"},
+        {
+            RPCResult{RPCResult::Type::STR, "", "The help text"},
+            RPCResult{RPCResult::Type::ANY, "", ""},
+        },
         RPCExamples{""},
         [&](const RPCHelpMan &self, const Config &config,
             const JSONRPCRequest &jsonRequest) -> UniValue {
diff --git a/src/rpc/util.h b/src/rpc/util.h
--- a/src/rpc/util.h
+++ b/src/rpc/util.h
@@ -249,6 +249,7 @@
         NUM,
         BOOL,
         NONE,
+        ANY,        //!< Special type to disable type checks (for testing only)
         STR_AMOUNT, //!< Special string to represent a floating point amount
         STR_HEX,    //!< Special string with only hex chars
         OBJ_DYN,    //!< Special dictionary with keys that are not literals
@@ -305,6 +306,8 @@
     std::string ToStringObj() const;
     /** Return the description string, including the result type. */
     std::string ToDescriptionString() const;
+    /** Check whether the result JSON type matches. */
+    bool MatchesType(const UniValue &result) const;
 };
 
 struct RPCResults {
@@ -339,7 +342,8 @@
                std::vector<RPCArg> args, RPCResults results,
                RPCExamples examples, RPCMethodImpl fun);
 
-    UniValue HandleRequest(const Config &config, const JSONRPCRequest &request);
+    UniValue HandleRequest(const Config &config,
+                           const JSONRPCRequest &request) const;
     std::string ToString() const;
     /**
      * Return the named args that need to be converted from string to another
diff --git a/src/rpc/util.cpp b/src/rpc/util.cpp
--- a/src/rpc/util.cpp
+++ b/src/rpc/util.cpp
@@ -470,7 +470,12 @@
 
 std::string RPCResults::ToDescriptionString() const {
     std::string result;
+
     for (const auto &r : m_results) {
+        if (r.m_type == RPCResult::Type::ANY) {
+            // for testing only
+            continue;
+        }
         if (r.m_cond.empty()) {
             result += "\nResult:\n";
         } else {
@@ -488,7 +493,7 @@
 }
 
 UniValue RPCHelpMan::HandleRequest(const Config &config,
-                                   const JSONRPCRequest &request) {
+                                   const JSONRPCRequest &request) const {
     if (request.mode == JSONRPCRequest::GET_ARGS) {
         return GetArgMap();
     }
@@ -500,7 +505,11 @@
         !IsValidNumArgs(request.params.size())) {
         throw std::runtime_error(ToString());
     }
-    return m_fun(*this, config, request);
+    const UniValue ret = m_fun(*this, config, request);
+    CHECK_NONFATAL(std::any_of(
+        m_results.m_results.begin(), m_results.m_results.end(),
+        [ret](const RPCResult &res) { return res.MatchesType(ret); }));
+    return ret;
 }
 
 bool RPCHelpMan::IsValidNumArgs(size_t num_args) const {
@@ -716,6 +725,10 @@
                 {indent + "..." + maybe_separator, m_description});
             return;
         }
+        case Type::ANY: {
+            // Only for testing
+            CHECK_NONFATAL(false);
+        }
         case Type::NONE: {
             sections.PushSection(
                 {indent + "null" + maybe_separator, Description("json null")});
@@ -795,6 +808,41 @@
     CHECK_NONFATAL(false);
 }
 
+bool RPCResult::MatchesType(const UniValue &result) const {
+    switch (m_type) {
+        case Type::ELISION: {
+            return false;
+        }
+        case Type::ANY: {
+            return true;
+        }
+        case Type::NONE: {
+            return UniValue::VNULL == result.getType();
+        }
+        case Type::STR:
+        case Type::STR_HEX: {
+            return UniValue::VSTR == result.getType();
+        }
+        case Type::NUM:
+        case Type::STR_AMOUNT:
+        case Type::NUM_TIME: {
+            return UniValue::VNUM == result.getType();
+        }
+        case Type::BOOL: {
+            return UniValue::VBOOL == result.getType();
+        }
+        case Type::ARR_FIXED:
+        case Type::ARR: {
+            return UniValue::VARR == result.getType();
+        }
+        case Type::OBJ_DYN:
+        case Type::OBJ: {
+            return UniValue::VOBJ == result.getType();
+        }
+    } // no default case, so the compiler can warn about missing cases
+    CHECK_NONFATAL(false);
+}
+
 std::string RPCArg::ToStringObj(const bool oneline) const {
     std::string res;
     res += "\"";