diff --git a/src/wuttjamaican/conf.py b/src/wuttjamaican/conf.py
index 2c71e28..fd23388 100644
--- a/src/wuttjamaican/conf.py
+++ b/src/wuttjamaican/conf.py
@@ -252,34 +252,44 @@ class WuttaConfig:
         if path in self.files_read:
             return
 
-        # try to load config from the given path
-        try:
-            config = configuration.config_from_ini(path, read_from_file=True)
-        except FileNotFoundError:
-            if not require:
-                log.warning("INI config file not found: %s", path)
-                return
-            raise
+        # try to load config with standard parser, and default vars
+        here = os.path.dirname(path)
+        config = configparser.ConfigParser(defaults={'here': here, '__file__': path})
+        if not config.read(path):
+            if require:
+                raise FileNotFoundError(f"could not read required config file: {path}")
+            return
 
-        # ok add that one to the mix
+        # load all values into (yet another) temp config
+        temp_config = configparser.RawConfigParser()
+        for section in config.sections():
+            temp_config.add_section(section)
+            # nb. must interpolate most values but *not* for logging formatters
+            raw = section.startswith('formatter_')
+            for option in config.options(section):
+                temp_config.set(section, option, config.get(section, option, raw=raw))
+
+        # re-write as temp file with "final" values
+        fd, temp_path = tempfile.mkstemp(suffix='.ini')
+        os.close(fd)
+        with open(temp_path, 'wt') as f:
+            temp_config.write(f)
+
+        # and finally, load that into our main config
+        config = configuration.config_from_ini(temp_path, read_from_file=True)
         configs.append(config)
         self.files_read.append(path)
 
-        # need parent folder of that path, for %(here)s interpolation
-        here = os.path.dirname(path)
-
         # bring in any "required" files
         requires = config.get(f'{self.appname}.config.require')
         if requires:
             for path in self.parse_list(requires):
-                path = path % {'here': here}
                 self._load_ini_configs(path, configs, require=True)
 
         # bring in any "included" files
         includes = config.get(f'{self.appname}.config.include')
         if includes:
             for path in self.parse_list(includes):
-                path = path % {'here': here}
                 self._load_ini_configs(path, configs, require=False)
 
     def get_prioritized_files(self):
diff --git a/tests/test_conf.py b/tests/test_conf.py
index b5b8771..5b46539 100644
--- a/tests/test_conf.py
+++ b/tests/test_conf.py
@@ -159,6 +159,17 @@ require = %(here)s/first.conf
         self.assertEqual(files[0], second)
         self.assertEqual(files[1], first)
 
+    def test_default_vars_interpolated(self):
+        myconf = self.write_file('my.conf', """
+[foo]
+bar = %(here)s/bar.txt
+baz = %(__file__)s
+""")
+
+        config = conf.WuttaConfig(files=[myconf])
+        self.assertEqual(config.get('foo.bar'), f'{self.tempdir}/bar.txt')
+        self.assertEqual(config.get('foo.baz'), myconf)
+
     def test_constructor_defaults(self):
         config = conf.WuttaConfig()
         self.assertEqual(config.defaults, {})