diff --git a/requirements.txt b/requirements.txt
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,6 +2,6 @@
 pygments
 click
 chardet
-file_magic
+python-magic
 pyld
 xmltodict
diff --git a/swh/indexer/mimetype.py b/swh/indexer/mimetype.py
--- a/swh/indexer/mimetype.py
+++ b/swh/indexer/mimetype.py
@@ -5,8 +5,6 @@
 
 import magic
 
-from swh.model import hashutil
-
 from .indexer import ContentIndexer, ContentRangeIndexer
 
 
@@ -21,10 +19,18 @@
         (as bytes).
 
     """
-    r = magic.detect_from_content(raw_content)
+    if hasattr(magic.Magic, 'from_buffer'):
+        # https://pypi.org/project/python-magic/
+        m = magic.Magic(mime=True, mime_encoding=True)
+        res = m.from_buffer(raw_content)
+        (mimetype, encoding) = res.split('; charset=')
+    else:
+        # https://pypi.org/project/file-magic/
+        r = magic.detect_from_content(raw_content)
+        (mimetype, encoding) = (r.mime_type, r.encoding)
     return {
-        'mimetype': r.mime_type,
-        'encoding': r.encoding,
+        'mimetype': mimetype,
+        'encoding': encoding,
     }
 
 
@@ -67,17 +73,11 @@
             - **encoding** (bytes): encoding in bytes
 
         """
-        try:
-            properties = compute_mimetype_encoding(data)
-            properties.update({
-                'id': id,
-                'indexer_configuration_id': self.tool['id'],
-                })
-        except TypeError:
-            self.log.error('Detecting mimetype error for id %s' % (
-                hashutil.hash_to_hex(id), ))
-            return None
-
+        properties = compute_mimetype_encoding(data)
+        properties.update({
+            'id': id,
+            'indexer_configuration_id': self.tool['id'],
+            })
         return properties
 
     def persist_index_computations(self, results, policy_update):