diff --git a/src/bitcoind.cpp b/src/bitcoind.cpp
--- a/src/bitcoind.cpp
+++ b/src/bitcoind.cpp
@@ -113,7 +113,7 @@
                     gArgs.GetArg("-datadir", "").c_str());
             return false;
         }
-        if (!gArgs.ReadConfigFiles(error)) {
+        if (!gArgs.ReadConfigFiles(error, true)) {
             fprintf(stderr, "Error reading configuration file: %s\n",
                     error.c_str());
             return false;
diff --git a/src/interfaces/node.cpp b/src/interfaces/node.cpp
--- a/src/interfaces/node.cpp
+++ b/src/interfaces/node.cpp
@@ -59,7 +59,7 @@
             return gArgs.ParseParameters(argc, argv, error);
         }
         bool readConfigFiles(std::string &error) override {
-            return gArgs.ReadConfigFiles(error);
+            return gArgs.ReadConfigFiles(error, true);
         }
         bool softSetArg(const std::string &arg,
                         const std::string &value) override {
diff --git a/src/util/system.cpp b/src/util/system.cpp
--- a/src/util/system.cpp
+++ b/src/util/system.cpp
@@ -942,10 +942,15 @@
         }
 
         // Check that the arg is known
-        if (!IsArgKnown(strKey) && !ignore_invalid_keys) {
-            error = strprintf("Invalid configuration value %s",
-                              option.first.c_str());
-            return false;
+        if (!IsArgKnown(strKey)) {
+            if (!ignore_invalid_keys) {
+                error = strprintf("Invalid configuration value %s",
+                                  option.first.c_str());
+                return false;
+            } else {
+                LogPrintf("Ignoring unknown configuration value %s\n",
+                          option.first);
+            }
         }
     }
     return true;
diff --git a/test/functional/feature_includeconf.py b/test/functional/feature_includeconf.py
--- a/test/functional/feature_includeconf.py
+++ b/test/functional/feature_includeconf.py
@@ -60,10 +60,13 @@
             0, expected_stderr="warning: -includeconf cannot be used from included files; ignoring -includeconf=relative2.conf")
 
         self.log.info("-includeconf cannot contain invalid arg")
-        with open(os.path.join(self.options.tmpdir, "node0", "relative.conf"), "w", encoding="utf8") as f:
-            f.write("foo=bar\n")
-        self.nodes[0].assert_start_raises_init_error(
-            expected_msg="Error reading configuration file: Invalid configuration value foo")
+
+        # Commented out as long as we ignore invalid arguments in configuration files
+        # with open(os.path.join(self.options.tmpdir, "node0", "relative.conf"), "w", encoding="utf8") as f:
+        #     f.write("foo=bar\n")
+        # self.nodes[0].assert_start_raises_init_error(
+        #     expected_msg="Error reading configuration file: Invalid configuration value foo")
+        # See https://github.com/bitcoin/bitcoin/pull/13799
 
         self.log.info("-includeconf cannot be invalid path")
         os.remove(os.path.join(self.options.tmpdir, "node0", "relative.conf"))