diff --git a/swh/deposit/tests/api/test_checks.py b/swh/deposit/tests/api/test_checks.py
--- a/swh/deposit/tests/api/test_checks.py
+++ b/swh/deposit/tests/api/test_checks.py
@@ -29,7 +29,7 @@
 XMLNS = """xmlns="http://www.w3.org/2005/Atom"
                    xmlns:swh="https://www.softwareheritage.org/schema/2018/deposit"
                    xmlns:codemeta="https://doi.org/10.5063/SCHEMA/CODEMETA-2.0"
-                   xmlns:schema="http://schema.org/" """
+                   xmlns:schema="https://schema.org/" """
 
 PROVENANCE_XML = """
                 <swh:deposit>
@@ -480,7 +480,7 @@
             <entry xmlns:atom="http://www.w3.org/2005/Atom"
                    xmlns:swh="https://www.softwareheritage.org/schema/2018/deposit"
                    xmlns:codemeta="https://doi.org/10.5063/SCHEMA/CODEMETA-2.0"
-                   xmlns:schema="http://schema.org/">
+                   xmlns:schema="https://schema.org/">
                 <atom:url>something</atom:url>
                 <atom:external_identifier>something-else</atom:external_identifier>
                 <atom:title>foobar</atom:title>
diff --git a/swh/deposit/tests/data/atom/entry-data-with-add-to-origin-no-prov.xml b/swh/deposit/tests/data/atom/entry-data-with-add-to-origin-no-prov.xml
--- a/swh/deposit/tests/data/atom/entry-data-with-add-to-origin-no-prov.xml
+++ b/swh/deposit/tests/data/atom/entry-data-with-add-to-origin-no-prov.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0"?>
 <entry xmlns="http://www.w3.org/2005/Atom"
        xmlns:codemeta="https://doi.org/10.5063/SCHEMA/CODEMETA-2.0"
-       xmlns:schema="http://schema.org/"
+       xmlns:schema="https://schema.org/"
        xmlns:swh="https://www.softwareheritage.org/schema/2018/deposit">
     <title>Awesome Compiler</title>
     <id>urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a</id>
diff --git a/swh/deposit/tests/data/atom/entry-data-with-add-to-origin.xml b/swh/deposit/tests/data/atom/entry-data-with-add-to-origin.xml
--- a/swh/deposit/tests/data/atom/entry-data-with-add-to-origin.xml
+++ b/swh/deposit/tests/data/atom/entry-data-with-add-to-origin.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0"?>
 <entry xmlns="http://www.w3.org/2005/Atom"
        xmlns:codemeta="https://doi.org/10.5063/SCHEMA/CODEMETA-2.0"
-       xmlns:schema="http://schema.org/"
+       xmlns:schema="https://schema.org/"
        xmlns:swh="https://www.softwareheritage.org/schema/2018/deposit">
     <title>Awesome Compiler</title>
     <id>urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a</id>
diff --git a/swh/deposit/tests/data/atom/entry-data-with-metadata-provenance.xml b/swh/deposit/tests/data/atom/entry-data-with-metadata-provenance.xml
--- a/swh/deposit/tests/data/atom/entry-data-with-metadata-provenance.xml
+++ b/swh/deposit/tests/data/atom/entry-data-with-metadata-provenance.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0"?>
 <entry xmlns="http://www.w3.org/2005/Atom"
-       xmlns:schema="http://schema.org/"
+       xmlns:schema="https://schema.org/"
        xmlns:swh="https://www.softwareheritage.org/schema/2018/deposit">
     <title>Awesome stuff</title>
     <id>urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a</id>
diff --git a/swh/deposit/tests/data/atom/entry-data-with-swhid.xml b/swh/deposit/tests/data/atom/entry-data-with-swhid.xml
--- a/swh/deposit/tests/data/atom/entry-data-with-swhid.xml
+++ b/swh/deposit/tests/data/atom/entry-data-with-swhid.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0"?>
 <entry xmlns="http://www.w3.org/2005/Atom"
          xmlns:codemeta="https://doi.org/10.5063/SCHEMA/CODEMETA-2.0"
-         xmlns:schema="http://schema.org/"
+         xmlns:schema="https://schema.org/"
          xmlns:swh="https://www.softwareheritage.org/schema/2018/deposit">
     <title>Awesome Compiler</title>
     <id>urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a</id>
diff --git a/swh/deposit/tests/data/atom/entry-only-create-origin.xml b/swh/deposit/tests/data/atom/entry-only-create-origin.xml
--- a/swh/deposit/tests/data/atom/entry-only-create-origin.xml
+++ b/swh/deposit/tests/data/atom/entry-only-create-origin.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0"?>
 <entry xmlns="http://www.w3.org/2005/Atom"
-       xmlns:schema="http://schema.org/"
+       xmlns:schema="https://schema.org/"
        xmlns:swh="https://www.softwareheritage.org/schema/2018/deposit">
     <swh:deposit>
       <swh:create_origin>
diff --git a/swh/deposit/tests/test_utils.py b/swh/deposit/tests/test_utils.py
--- a/swh/deposit/tests/test_utils.py
+++ b/swh/deposit/tests/test_utils.py
@@ -114,7 +114,7 @@
 def xml_swh_deposit_template():
     xml_data = """<?xml version="1.0"?>
   <entry xmlns:swh="https://www.softwareheritage.org/schema/2018/deposit"
-         xmlns:schema="http://schema.org/">
+         xmlns:schema="https://schema.org/">
       <swh:deposit>
         {swh_deposit}
       </swh:deposit>
diff --git a/swh/deposit/utils.py b/swh/deposit/utils.py
--- a/swh/deposit/utils.py
+++ b/swh/deposit/utils.py
@@ -23,7 +23,7 @@
     "codemeta": "https://doi.org/10.5063/SCHEMA/CODEMETA-2.0",
     "sword": "http://purl.org/net/sword/terms/",
     "swh": "https://www.softwareheritage.org/schema/2018/deposit",
-    "schema": "http://schema.org/",
+    "schema": "https://schema.org/",
 }