diff --git a/test/certs/pkitsta.pem b/test/certs/pkitsta.pem
new file mode 100644
index 0000000000..4cb5ec5b95
--- /dev/null
+++ b/test/certs/pkitsta.pem
@@ -0,0 +1,20 @@
+-----BEGIN CERTIFICATE-----
+MIIDRzCCAi+gAwIBAgIBATANBgkqhkiG9w0BAQsFADBFMQswCQYDVQQGEwJVUzEf
+MB0GA1UEChMWVGVzdCBDZXJ0aWZpY2F0ZXMgMjAxMTEVMBMGA1UEAxMMVHJ1c3Qg
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+D/jYbVwQMXLqn1pjJttOPJwuA8+ho1f2c8FrKlqjHgOwxuHhsiGN6MKgs1baalpR
+/lnNFCIpq+/+3cnhufDjvxMy5lg+cwgMCiGzCxn4n4dBMw41C+4KhNF7ZtKuKSZ1
+eczztXD9NUkGUGw3LzpLDJazz3JhlZ/9pXzF
+-----END CERTIFICATE-----
diff --git a/test/recipes/80-test_cms.t b/test/recipes/80-test_cms.t
index 28d96b8eda..5d755c989d 100644
--- a/test/recipes/80-test_cms.t
+++ b/test/recipes/80-test_cms.t
@@ -50,7 +50,7 @@ my ($no_des, $no_dh, $no_dsa, $no_ec, $no_ec2m, $no_rc2, $no_zlib)
 
 $no_rc2 = 1 if disabled("legacy");
 
-plan tests => 15;
+plan tests => 16;
 
 ok(run(test(["pkcs7_test"])), "test pkcs7");
 
@@ -1081,3 +1081,14 @@ sub check_availability {
 
     return "";
 }
+
+# Test case for the locking problem reported in #19643.
+# This will fail if the fix is in and deadlock on Windows (and possibly
+# other platforms) if not.
+ok(!run(app(['openssl', 'cms', '-verify',
+             '-CAfile', srctop_file("test/certs", "pkitsta.pem"),
+             '-policy', 'anyPolicy',
+             '-in', srctop_file("test/smime-eml",
+                                "SignedInvalidMappingFromanyPolicyTest7.eml")
+            ])),
+   "issue#19643");
diff --git a/test/smime-eml/SignedInvalidMappingFromanyPolicyTest7.eml b/test/smime-eml/SignedInvalidMappingFromanyPolicyTest7.eml
new file mode 100644
index 0000000000..5d6b49d2c1
--- /dev/null
+++ b/test/smime-eml/SignedInvalidMappingFromanyPolicyTest7.eml
@@ -0,0 +1,93 @@
+To: recipient@testcertificates.gov
+From: sender@testcertificates.gov
+Subject: Invalid Mapping From anyPolicy Test7
+MIME-Version: 1.0
+Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg="sha-256"; boundary="----C124D5D1A319E09E6A4BB51A44961168"
+
+This is an S/MIME signed message
+
+------C124D5D1A319E09E6A4BB51A44961168
+Content-Type: text/plain
+
+This is a sample signed message.
+
+------C124D5D1A319E09E6A4BB51A44961168
+Content-Type: application/pkcs7-signature; name="smime.p7s"
+Content-Transfer-Encoding: base64
+Content-Disposition: attachment; filename="smime.p7s"
+
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+
+------C124D5D1A319E09E6A4BB51A44961168--
+