diff --git a/sql/upgrades/117.sql b/sql/upgrades/117.sql
--- a/sql/upgrades/117.sql
+++ b/sql/upgrades/117.sql
@@ -3,6 +3,9 @@
 -- to_version: 117
 -- description: Add fulltext search index for origin intrinsic metadata
 
+insert into dbversion(version, release, description)
+values(117, now(), 'Work In Progress');
+
 alter table origin_intrinsic_metadata add column metadata_tsvector tsvector;
 update origin_intrinsic_metadata set metadata_tsvector = to_tsvector('pg_catalog.simple', metadata);
 create index origin_intrinsic_metadata_fulltext_idx on origin_intrinsic_metadata using gin (metadata_tsvector);
diff --git a/sql/upgrades/118.sql b/sql/upgrades/118.sql
new file mode 100644
--- /dev/null
+++ b/sql/upgrades/118.sql
@@ -0,0 +1,11 @@
+-- SWH Indexer DB schema upgrade
+-- from_version: 117
+-- to_version: 118
+-- description: content_mimetype: Migrate bytes column to text
+
+insert into dbversion(version, release, description)
+values(118, now(), 'Work In Progress');
+
+alter table content_mimetype
+  alter column mimetype set data type text,
+  alter column encoding set data type text;
diff --git a/swh/indexer/mimetype.py b/swh/indexer/mimetype.py
--- a/swh/indexer/mimetype.py
+++ b/swh/indexer/mimetype.py
@@ -23,8 +23,8 @@
     """
     r = magic.detect_from_content(raw_content)
     return {
-        'mimetype': r.mime_type.encode('utf-8'),
-        'encoding': r.encoding.encode('utf-8'),
+        'mimetype': r.mime_type,
+        'encoding': r.encoding,
     }
 
 
diff --git a/swh/indexer/sql/30-swh-schema.sql b/swh/indexer/sql/30-swh-schema.sql
--- a/swh/indexer/sql/30-swh-schema.sql
+++ b/swh/indexer/sql/30-swh-schema.sql
@@ -14,7 +14,7 @@
 );
 
 insert into dbversion(version, release, description)
-      values(116, now(), 'Work In Progress');
+      values(117, now(), 'Work In Progress');
 -- Computing metadata on sha1's contents
 
 -- a SHA1 checksum (not necessarily originating from Git)
@@ -39,8 +39,8 @@
 -- Properties (mimetype, encoding, etc...)
 create table content_mimetype (
   id sha1 not null,
-  mimetype bytea not null,
-  encoding bytea not null,
+  mimetype text not null,
+  encoding text not null,
   indexer_configuration_id bigint not null
 );
 
diff --git a/swh/indexer/tests/storage/test_storage.py b/swh/indexer/tests/storage/test_storage.py
--- a/swh/indexer/tests/storage/test_storage.py
+++ b/swh/indexer/tests/storage/test_storage.py
@@ -116,8 +116,8 @@
         # given
         self.storage.content_mimetype_add([{
             'id': self.sha1_2,
-            'mimetype': b'text/plain',
-            'encoding': b'utf-8',
+            'mimetype': 'text/plain',
+            'encoding': 'utf-8',
             'indexer_configuration_id': tool_id,
         }])
 
@@ -133,8 +133,8 @@
 
         mimetype_v1 = {
             'id': self.sha1_2,
-            'mimetype': b'text/plain',
-            'encoding': b'utf-8',
+            'mimetype': 'text/plain',
+            'encoding': 'utf-8',
             'indexer_configuration_id': tool_id,
         }
 
@@ -148,8 +148,8 @@
         # then
         expected_mimetypes_v1 = [{
             'id': self.sha1_2,
-            'mimetype': b'text/plain',
-            'encoding': b'utf-8',
+            'mimetype': 'text/plain',
+            'encoding': 'utf-8',
             'tool': self.tools['file'],
         }]
         self.assertEqual(actual_mimetypes, expected_mimetypes_v1)
@@ -157,8 +157,8 @@
         # given
         mimetype_v2 = mimetype_v1.copy()
         mimetype_v2.update({
-            'mimetype': b'text/html',
-            'encoding': b'us-ascii',
+            'mimetype': 'text/html',
+            'encoding': 'us-ascii',
         })
 
         self.storage.content_mimetype_add([mimetype_v2])
@@ -175,8 +175,8 @@
 
         mimetype_v1 = {
             'id': self.sha1_2,
-            'mimetype': b'text/plain',
-            'encoding': b'utf-8',
+            'mimetype': 'text/plain',
+            'encoding': 'utf-8',
             'indexer_configuration_id': tool_id,
         }
 
@@ -189,8 +189,8 @@
 
         expected_mimetypes_v1 = [{
             'id': self.sha1_2,
-            'mimetype': b'text/plain',
-            'encoding': b'utf-8',
+            'mimetype': 'text/plain',
+            'encoding': 'utf-8',
             'tool': self.tools['file'],
         }]
 
@@ -200,8 +200,8 @@
         # given
         mimetype_v2 = mimetype_v1.copy()
         mimetype_v2.update({
-            'mimetype': b'text/html',
-            'encoding': b'us-ascii',
+            'mimetype': 'text/html',
+            'encoding': 'us-ascii',
         })
 
         self.storage.content_mimetype_add([mimetype_v2], conflict_update=True)
@@ -211,8 +211,8 @@
 
         expected_mimetypes_v2 = [{
             'id': self.sha1_2,
-            'mimetype': b'text/html',
-            'encoding': b'us-ascii',
+            'mimetype': 'text/html',
+            'encoding': 'us-ascii',
             'tool': {
                 'id': 2,
                 'name': 'file',
@@ -232,8 +232,8 @@
 
         mimetype1 = {
             'id': self.sha1_2,
-            'mimetype': b'text/plain',
-            'encoding': b'utf-8',
+            'mimetype': 'text/plain',
+            'encoding': 'utf-8',
             'indexer_configuration_id': tool_id,
         }
 
@@ -246,8 +246,8 @@
         # then
         expected_mimetypes = [{
             'id': self.sha1_2,
-            'mimetype': b'text/plain',
-            'encoding': b'utf-8',
+            'mimetype': 'text/plain',
+            'encoding': 'utf-8',
             'tool': self.tools['file']
         }]
 
diff --git a/swh/indexer/tests/test_mimetype.py b/swh/indexer/tests/test_mimetype.py
--- a/swh/indexer/tests/test_mimetype.py
+++ b/swh/indexer/tests/test_mimetype.py
@@ -37,8 +37,8 @@
 
             actual_result = compute_mimetype_encoding(_input)
             self.assertEqual(actual_result, {
-                'mimetype': _mimetype.encode('utf-8'),
-                'encoding': _encoding.encode('utf-8'),
+                'mimetype': _mimetype,
+                'encoding': _encoding
             })
 
 
@@ -83,20 +83,20 @@
             self.id0: {
                 'id': self.id0,
                 'indexer_configuration_id': tool_id,
-                'mimetype': b'text/plain',
-                'encoding': b'us-ascii',
+                'mimetype': 'text/plain',
+                'encoding': 'us-ascii',
             },
             self.id1: {
                 'id': self.id1,
                 'indexer_configuration_id': tool_id,
-                'mimetype': b'text/plain',
-                'encoding': b'us-ascii',
+                'mimetype': 'text/plain',
+                'encoding': 'us-ascii',
             },
             self.id2: {
                 'id': self.id2,
                 'indexer_configuration_id': tool_id,
-                'mimetype': b'application/x-empty',
-                'encoding': b'binary',
+                'mimetype': 'application/x-empty',
+                'encoding': 'binary',
             }
         }
 
@@ -154,20 +154,20 @@
 
         self.expected_results = {
             self.id0: {
-                'encoding': b'us-ascii',
+                'encoding': 'us-ascii',
                 'id': self.id0,
                 'indexer_configuration_id': tool_id,
-                'mimetype': b'text/plain'},
+                'mimetype': 'text/plain'},
             self.id1: {
-                'encoding': b'us-ascii',
+                'encoding': 'us-ascii',
                 'id': self.id1,
                 'indexer_configuration_id': tool_id,
-                'mimetype': b'text/x-python'},
+                'mimetype': 'text/x-python'},
             self.id2: {
-                'encoding': b'us-ascii',
+                'encoding': 'us-ascii',
                 'id': self.id2,
                 'indexer_configuration_id': tool_id,
-                'mimetype': b'text/plain'}
+                'mimetype': 'text/plain'}
         }