diff --git a/tests/scripts/depends.py b/tests/scripts/depends.py
index 0d6ec94..86e8fff 100755
--- a/tests/scripts/depends.py
+++ b/tests/scripts/depends.py
@@ -23,7 +23,7 @@
 This script can be divided into several steps:
 
 First, include/mbedtls/mbedtls_config.h or a different config file passed
-in the arguments is parsed to extract any configuration options (collect_config_symbols).
+in the arguments is parsed to extract any configuration options (using config.py).
 
 Then, test domains (groups of jobs, tests) are built based on predefined data
 collected in the DomainData class. Here, each domain has five major traits:
@@ -72,6 +72,9 @@
 import sys
 import traceback
 
+import scripts_path # pylint: disable=unused-import
+import config
+
 class Colors: # pylint: disable=too-few-public-methods
     """Minimalistic support for colored output.
 Each field of an object of this class is either None if colored output
@@ -80,6 +83,7 @@
 stop switches the text color back to the default."""
     red = None
     green = None
+    cyan = None
     bold_red = None
     bold_green = None
     def __init__(self, options=None):
@@ -95,6 +99,7 @@
             normal = '\033[0m'
             self.red = ('\033[31m', normal)
             self.green = ('\033[32m', normal)
+            self.cyan = ('\033[36m', normal)
             self.bold_red = ('\033[1;31m', normal)
             self.bold_green = ('\033[1;32m', normal)
 NO_COLORS = Colors(None)
@@ -130,34 +135,39 @@
     else:
         shutil.copy(options.config_backup, options.config)
 
-def run_config_py(options, args):
-    """Run scripts/config.py with the specified arguments."""
-    cmd = ['scripts/config.py']
-    if options.config != 'include/mbedtls/mbedtls_config.h':
-        cmd += ['--file', options.config]
-    cmd += args
-    log_command(cmd)
-    subprocess.check_call(cmd)
+def option_exists(conf, option):
+    if option not in conf.settings:
+        return False
+    return True
 
-def set_reference_config(options):
+def set_config_option(conf, option, colors, value=None):
+    """Set configuration option, optionally specifying a value"""
+    if not option_exists(conf, option):
+        log_line('Symbol {} was not found in {}'.format(option, conf.filename), color=colors.red)
+        return False
+    log_command(['config.py', 'set', option])
+    conf.set(option, value)
+    return True
+
+def unset_config_option(conf, option, colors):
+    """Unset configuration option if it exists"""
+    if not option_exists(conf, option):
+        log_line('Symbol {} was not found in {}'.format(option, conf.filename), color=colors.red)
+        return False
+    log_command(['config.py', 'unset', option])
+    conf.unset(option)
+    return True
+
+def set_reference_config(conf, options, colors):
     """Change the library configuration file (mbedtls_config.h) to the reference state.
 The reference state is the one from which the tested configurations are
 derived."""
     # Turn off options that are not relevant to the tests and slow them down.
-    run_config_py(options, ['full'])
-    run_config_py(options, ['unset', 'MBEDTLS_TEST_HOOKS'])
+    log_command(['config.py', 'full'])
+    conf.adapt(config.full_adapter)
+    unset_config_option(conf, 'MBEDTLS_TEST_HOOKS', colors)
     if options.unset_use_psa:
-        run_config_py(options, ['unset', 'MBEDTLS_USE_PSA_CRYPTO'])
-
-def collect_config_symbols(options):
-    """Read the list of settings from mbedtls_config.h.
-Return them in a generator."""
-    with open(options.config, encoding="utf-8") as config_file:
-        rx = re.compile(r'\s*(?://\s*)?#define\s+(\w+)\s*(?:$|/[/*])')
-        for line in config_file:
-            m = re.match(rx, line)
-            if m:
-                yield m.group(1)
+        unset_config_option(conf, 'MBEDTLS_USE_PSA_CRYPTO', colors)
 
 class Job:
     """A job builds the library in a specific configuration and runs some tests."""
@@ -185,19 +195,22 @@
         elif what is False:
             log_line(self.name + ' FAILED', color=colors.red)
         else:
-            log_line('starting ' + self.name)
+            log_line('starting ' + self.name, color=colors.cyan)
 
-    def configure(self, options):
+    def configure(self, conf, options, colors):
         '''Set library configuration options as required for the job.'''
-        set_reference_config(options)
+        set_reference_config(conf, options, colors)
         for key, value in sorted(self.config_settings.items()):
+            ret = False
             if value is True:
-                args = ['set', key]
+                ret = set_config_option(conf, key, colors)
             elif value is False:
-                args = ['unset', key]
+                ret = unset_config_option(conf, key, colors)
             else:
-                args = ['set', key, value]
-            run_config_py(options, args)
+                ret = set_config_option(conf, key, colors, value)
+            if ret is False:
+                return False
+        return True
 
     def test(self, options):
         '''Run the job's build and test commands.
@@ -392,11 +405,11 @@
         return [symbol for symbol in self.all_config_symbols
                 if re.match(regexp, symbol)]
 
-    def __init__(self, options):
+    def __init__(self, options, conf):
         """Gather data about the library and establish a list of domains to test."""
         build_command = [options.make_command, 'CFLAGS=-Werror']
         build_and_test = [build_command, [options.make_command, 'test']]
-        self.all_config_symbols = set(collect_config_symbols(options))
+        self.all_config_symbols = set(conf.settings.keys())
         # Find hash modules by name.
         hash_symbols = self.config_symbols_matching(r'MBEDTLS_(MD|RIPEMD|SHA)[0-9]+_C\Z')
         # Find elliptic curve enabling macros by name.
@@ -455,16 +468,19 @@
         else:
             return [self.jobs[name]]
 
-def run(options, job, colors=NO_COLORS):
+def run(options, job, conf, colors=NO_COLORS):
     """Run the specified job (a Job instance)."""
     subprocess.check_call([options.make_command, 'clean'])
     job.announce(colors, None)
-    job.configure(options)
+    if not job.configure(conf, options, colors):
+        job.announce(colors, False)
+        return False
+    conf.write()
     success = job.test(options)
     job.announce(colors, success)
     return success
 
-def run_tests(options, domain_data):
+def run_tests(options, domain_data, conf):
     """Run the desired jobs.
 domain_data should be a DomainData instance that describes the available
 domains and jobs.
@@ -480,7 +496,7 @@
     backup_config(options)
     try:
         for job in jobs:
-            success = run(options, job, colors=colors)
+            success = run(options, job, conf, colors=colors)
             if not success:
                 if options.keep_going:
                     failures.append(job.name)
@@ -546,7 +562,9 @@
                             default=True)
         options = parser.parse_args()
         os.chdir(options.directory)
-        domain_data = DomainData(options)
+        conf = config.ConfigFile(options.config)
+        domain_data = DomainData(options, conf)
+
         if options.tasks is True:
             options.tasks = sorted(domain_data.domains.keys())
         if options.list:
@@ -555,7 +573,7 @@
                     print(domain_name)
             sys.exit(0)
         else:
-            sys.exit(0 if run_tests(options, domain_data) else 1)
+            sys.exit(0 if run_tests(options, domain_data, conf) else 1)
     except Exception: # pylint: disable=broad-except
         traceback.print_exc()
         sys.exit(3)