diff --git a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -14,6 +14,7 @@
 
 # Package information
 set(PACKAGE_NAME "Bitcoin ABC")
+set(PACKAGE_BUGREPORT "https://github.com/Bitcoin-ABC/bitcoin-abc/issues")
 
 # Copyright
 set(COPYRIGHT_YEAR 2020)
diff --git a/doc/release-notes.md b/doc/release-notes.md
--- a/doc/release-notes.md
+++ b/doc/release-notes.md
@@ -24,3 +24,5 @@
   the selected network. This change takes only effect if the selected network
   is not mainnet.
 
+ - The `echo` RPC will now return an internal bug report if exactly 100
+   arguments are provided.
diff --git a/src/Makefile.am b/src/Makefile.am
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -229,6 +229,7 @@
   undo.h \
   util/bitmanip.h \
   util/bytevectorhash.h \
+  util/check.h \
   util/moneystr.h \
   util/system.h \
   util/threadnames.h \
diff --git a/src/config/bitcoin-config.h.cmake.in b/src/config/bitcoin-config.h.cmake.in
--- a/src/config/bitcoin-config.h.cmake.in
+++ b/src/config/bitcoin-config.h.cmake.in
@@ -5,6 +5,8 @@
 
 #define PACKAGE_NAME "${PACKAGE_NAME}"
 
+#define PACKAGE_BUGREPORT "${PACKAGE_BUGREPORT}"
+
 #define COPYRIGHT_YEAR "${COPYRIGHT_YEAR}"
 #define COPYRIGHT_HOLDERS "${COPYRIGHT_HOLDERS}"
 #define COPYRIGHT_HOLDERS_SUBSTITUTION "${COPYRIGHT_HOLDERS_SUBSTITUTION}"
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -34,7 +34,6 @@
 
 #include <boost/thread/thread.hpp> // boost::thread::interrupt
 
-#include <cassert>
 #include <condition_variable>
 #include <cstdint>
 #include <memory>
diff --git a/src/rpc/misc.cpp b/src/rpc/misc.cpp
--- a/src/rpc/misc.cpp
+++ b/src/rpc/misc.cpp
@@ -17,6 +17,7 @@
 #include <rpc/server.h>
 #include <rpc/util.h>
 #include <timedata.h>
+#include <util/check.h>
 #include <util/strencodings.h>
 #include <util/system.h>
 #include <validation.h>
@@ -548,6 +549,8 @@
                 "echo|echojson ...",
                 "\nSimply echo back the input arguments. This command is for "
                 "testing.\n"
+                "\nIt will return an internal bug report when exactly 100 "
+                "arguments are passed.\n"
                 "\nThe difference between echo and echojson is that echojson "
                 "has argument conversion enabled in the client-side table in "
                 "bitcoin-cli and the GUI. There is no server-side difference.",
@@ -556,6 +559,8 @@
             "");
     }
 
+    CHECK_NONFATAL(request.params.size() != 100);
+
     return request.params;
 }
 
diff --git a/src/rpc/util.h b/src/rpc/util.h
--- a/src/rpc/util.h
+++ b/src/rpc/util.h
@@ -7,6 +7,7 @@
 
 #include <node/transaction.h>
 #include <script/standard.h> // For CTxDestination
+#include <util/check.h>
 
 #include <string>
 #include <vector>
@@ -78,7 +79,7 @@
         : m_name{name}, m_type{type}, m_optional{opt},
           m_default_value{default_val}, m_description{description},
           m_oneline_description{oneline_description}, m_type_str{type_str} {
-        assert(type != Type::ARR && type != Type::OBJ);
+        CHECK_NONFATAL(type != Type::ARR && type != Type::OBJ);
     }
 
     RPCArg(const std::string &name, const Type &type, const bool opt,
@@ -89,7 +90,7 @@
         : m_name{name}, m_type{type}, m_inner{inner}, m_optional{opt},
           m_default_value{default_val}, m_description{description},
           m_oneline_description{oneline_description}, m_type_str{type_str} {
-        assert(type == Type::ARR || type == Type::OBJ);
+        CHECK_NONFATAL(type == Type::ARR || type == Type::OBJ);
     }
 
     /**
diff --git a/src/util/check.h b/src/util/check.h
new file mode 100644
--- /dev/null
+++ b/src/util/check.h
@@ -0,0 +1,42 @@
+// Copyright (c) 2019 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_UTIL_CHECK_H
+#define BITCOIN_UTIL_CHECK_H
+
+#include <tinyformat.h>
+
+#include <stdexcept>
+
+class NonFatalCheckError : public std::runtime_error {
+    using std::runtime_error::runtime_error;
+};
+
+/**
+ * Throw a NonFatalCheckError when the condition evaluates to false
+ *
+ * This should only be used
+ * - where the condition is assumed to be true, not for error handling or
+ * validating user input
+ * - where a failure to fulfill the condition is recoverable and does not abort
+ * the program
+ *
+ * For example in RPC code, where it is undersirable to crash the whole program,
+ * this can be generally used to replace asserts or recoverable logic errors. A
+ * NonFatalCheckError in RPC code is caught and passed as a string to the RPC
+ * caller, which can then report the issue to the developers.
+ */
+#define CHECK_NONFATAL(condition)                                              \
+    do {                                                                       \
+        if (!(condition)) {                                                    \
+            throw NonFatalCheckError(                                          \
+                strprintf("%s:%d (%s)\n"                                       \
+                          "Internal bug detected: '%s'\n"                      \
+                          "You may report this issue here: %s\n",              \
+                          __FILE__, __LINE__, __func__, (#condition),          \
+                          PACKAGE_BUGREPORT));                                 \
+        }                                                                      \
+    } while (false)
+
+#endif // BITCOIN_UTIL_CHECK_H
diff --git a/test/functional/rpc_misc.py b/test/functional/rpc_misc.py
--- a/test/functional/rpc_misc.py
+++ b/test/functional/rpc_misc.py
@@ -23,6 +23,10 @@
     def run_test(self):
         node = self.nodes[0]
 
+        self.log.info("test CHECK_NONFATAL")
+        assert_raises_rpc_error(-1, "Internal bug detected: 'request.params.size() != 100'",
+                                lambda: node.echo(*[0] * 100),)
+
         self.log.info("test getmemoryinfo")
         memory = node.getmemoryinfo()['locked']
         assert_greater_than(memory['used'], 0)