diff --git a/mesonbuild/mintro.py b/mesonbuild/mintro.py
index 7bd420510..e3f2e51b1 100644
--- a/mesonbuild/mintro.py
+++ b/mesonbuild/mintro.py
@@ -64,8 +64,7 @@ class IntroCommand:
 
 def get_meson_introspection_types(coredata: T.Optional[cdata.CoreData] = None,
                                   builddata: T.Optional[build.Build] = None,
-                                  backend: T.Optional[backends.Backend] = None,
-                                  sourcedir: T.Optional[str] = None) -> 'T.Mapping[str, IntroCommand]':
+                                  backend: T.Optional[backends.Backend] = None) -> 'T.Mapping[str, IntroCommand]':
     if backend and builddata:
         benchmarkdata = backend.create_test_serialisation(builddata.get_benchmarks())
         testdata = backend.create_test_serialisation(builddata.get_tests())
@@ -543,7 +542,7 @@ def run(options: argparse.Namespace) -> int:
     indent = 4 if options.indent else None
     results: T.List[T.Tuple[str, T.Union[dict, T.List[T.Any]]]] = []
     sourcedir = '.' if options.builddir == 'meson.build' else options.builddir[:-11]
-    intro_types = get_meson_introspection_types(sourcedir=sourcedir)
+    intro_types = get_meson_introspection_types()
 
     if 'meson.build' in [os.path.basename(options.builddir), options.builddir]:
         # Make sure that log entries in other parts of meson don't interfere with the JSON output