diff --git a/meeteval/der/md_eval.py b/meeteval/der/md_eval.py
index d08a2f9c..4e2901e2 100644
--- a/meeteval/der/md_eval.py
+++ b/meeteval/der/md_eval.py
@@ -77,24 +77,16 @@ def __add__(self, other: 'DiaErrorRate'):
         )
 
 
-def _md_eval_22(
-        reference,
-        hypothesis,
-        average_out='{parent}/{stem}_md_eval_22.json',
-        per_reco_out='{parent}/{stem}_md_eval_22_per_reco.json',
-        collar=0,
-        regex=None,
-):
-    from meeteval.wer.__main__ import _load_texts
-
-    r, _, h, hypothesis_paths = _load_texts(
-        reference, hypothesis, regex)
+def md_eval_22_multifile(reference, hypothesis, collar=0):
+    from meeteval.io.rttm import RTTM
+    reference = RTTM.new(reference)
+    hypothesis = RTTM.new(hypothesis)
 
-    r = _fix_channel(r.to_rttm())
-    h = _fix_channel(h.to_rttm())
+    reference = _fix_channel(reference)
+    hypothesis = _fix_channel(hypothesis)
 
-    r = r.grouped_by_filename()
-    h = h.grouped_by_filename()
+    r = reference.grouped_by_filename()
+    h = hypothesis.grouped_by_filename()
 
     keys = set(r.keys()) & set(h.keys())
     missing = set(r.keys()) ^ set(h.keys())
@@ -135,7 +127,8 @@ def get_details(r, h, key, tmpdir):
         # SPEAKER ERROR TIME =0.000000 secs
         #  OVERALL SPEAKER DIARIZATION ERROR = 100.00 percent of scored speaker time  `(ALL)
 
-        error_rate, = re.findall(r'OVERALL SPEAKER DIARIZATION ERROR = ([\d.]+) percent of scored speaker time', cp.stdout)
+        error_rate, = re.findall(r'OVERALL SPEAKER DIARIZATION ERROR = ([\d.]+) percent of scored speaker time',
+                                 cp.stdout)
         length, = re.findall(r'SCORED SPEAKER TIME =([\d.]+) secs', cp.stdout)
         deletions, = re.findall(r'MISSED SPEAKER TIME =([\d.]+) secs', cp.stdout)
         insertions, = re.findall(r'FALARM SPEAKER TIME =([\d.]+) secs', cp.stdout)
@@ -173,6 +166,35 @@ def convert(string):
                 f'does not match the average error rate of md-eval-22.pl '
                 f'applied to each recording ({md_eval.error_rate}).'
             )
+    return per_reco
+
+
+def md_eval_22(reference, hypothesis, collar=0):
+    from meeteval.io.rttm import RTTM
+    reference = RTTM.new(reference, filename='dummy')
+    hypothesis = RTTM.new(hypothesis, filename='dummy')
+
+    assert len(reference.filenames()) == 1, reference.filenames()
+    assert len(hypothesis.filenames()) == 1, hypothesis.filenames()
+    assert reference.filenames() == hypothesis.filenames(), (reference.filenames(), hypothesis.filenames())
+
+    return md_eval_22_multifile(reference, hypothesis, collar)[reference.filenames()[0]]
+
+
+def _md_eval_22(
+        reference,
+        hypothesis,
+        average_out='{parent}/{stem}_md_eval_22.json',
+        per_reco_out='{parent}/{stem}_md_eval_22_per_reco.json',
+        collar=0,
+        regex=None,
+):
+    from meeteval.wer.__main__ import _load_texts
+
+    r, _, h, hypothesis_paths = _load_texts(
+        reference, hypothesis, regex)
+
+    per_reco = md_eval_22_multifile(r, h, collar)
 
     from meeteval.wer.__main__ import _save_results
     _save_results(per_reco, hypothesis_paths, per_reco_out, average_out)