diff --git a/dist/tools/kconfiglib/genconfig.py b/dist/tools/kconfiglib/genconfig.py
index ac72c62760..2fa52f51b3 100755
--- a/dist/tools/kconfiglib/genconfig.py
+++ b/dist/tools/kconfiglib/genconfig.py
@@ -393,9 +393,7 @@ with error.""")
     kconf = RiotKconfig(args.kconfig_filename, warn_to_stderr=False)
     merge_configs(kconf, args.config_sources)
 
-    # HACK: Force all symbols to be evaluated, to catch warnings generated
-    # during evaluation (such as out-of-range integers)
-    kconf.write_config(os.devnull, save_old=False)
+    kconf.evaluate_config()
 
     if not check_configs(kconf) and not args.ignore_config_errors:
         sys.exit(1)
diff --git a/dist/tools/kconfiglib/riot_kconfig.py b/dist/tools/kconfiglib/riot_kconfig.py
index be86733d65..c8a47a0800 100644
--- a/dist/tools/kconfiglib/riot_kconfig.py
+++ b/dist/tools/kconfiglib/riot_kconfig.py
@@ -28,6 +28,14 @@ class RiotKconfig(Kconfig):
         super(RiotKconfig, self).write_autoconf(filename, header)
         self.unique_defined_syms = tmp_unique_defined_syms
 
+    def evaluate_config(self):
+        """Evaluate the current configuration.
+
+        Useful to catch warnings (such as out-of-range integers) before writing
+        the configuration to a file.
+        """
+        self._config_contents(None)
+
 
 def standard_riot_kconfig(description=None):
     """