diff --git a/hack/prepare-for-integration-tests.sh b/hack/prepare-for-integration-tests.sh
index 76c5edf0..bb0fa104 100755
--- a/hack/prepare-for-integration-tests.sh
+++ b/hack/prepare-for-integration-tests.sh
@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 
-# Copyright 2020-2022 the Pinniped contributors. All Rights Reserved.
+# Copyright 2020-2023 the Pinniped contributors. All Rights Reserved.
 # SPDX-License-Identifier: Apache-2.0
 
 #
@@ -420,6 +420,7 @@ export PINNIPED_TEST_LDAP_USER_EMAIL_ATTRIBUTE_VALUE="pinny.ldap@example.com"
 export PINNIPED_TEST_LDAP_EXPECTED_DIRECT_GROUPS_DN="cn=ball-game-players,ou=beach-groups,ou=groups,dc=pinniped,dc=dev;cn=seals,ou=groups,dc=pinniped,dc=dev"
 export PINNIPED_TEST_LDAP_EXPECTED_INDIRECT_GROUPS_DN="cn=pinnipeds,ou=groups,dc=pinniped,dc=dev;cn=mammals,ou=groups,dc=pinniped,dc=dev"
 export PINNIPED_TEST_LDAP_EXPECTED_DIRECT_GROUPS_CN="ball-game-players;seals"
+export PINNIPED_TEST_LDAP_EXPECTED_DIRECT_POSIX_GROUPS_CN="ball-game-players-posix;seals-posix"
 export PINNIPED_TEST_LDAP_EXPECTED_INDIRECT_GROUPS_CN="pinnipeds;mammals"
 export PINNIPED_TEST_CLI_OIDC_ISSUER=https://dex.tools.svc.cluster.local/dex
 export PINNIPED_TEST_CLI_OIDC_ISSUER_CA_BUNDLE="${test_ca_bundle_pem}"
diff --git a/test/integration/supervisor_login_test.go b/test/integration/supervisor_login_test.go
index fb8efd09..511377b5 100644
--- a/test/integration/supervisor_login_test.go
+++ b/test/integration/supervisor_login_test.go
@@ -134,11 +134,13 @@ func TestSupervisorLogin_Browser(t *testing.T) {
 				},
 			},
 			GroupSearch: idpv1alpha1.LDAPIdentityProviderGroupSearch{
-				Base:   env.SupervisorUpstreamLDAP.GroupSearchBase,
-				Filter: "",
+				Base:                   env.SupervisorUpstreamLDAP.GroupSearchBase,
+				Filter:                 "",
+				UserAttributeForFilter: "",
 				Attributes: idpv1alpha1.LDAPIdentityProviderGroupSearchAttributes{
 					GroupName: "dn",
 				},
+				SkipGroupRefresh: false,
 			},
 		}
 
@@ -471,6 +473,38 @@ func TestSupervisorLogin_Browser(t *testing.T) {
 			},
 			wantDownstreamIDTokenGroups: env.SupervisorUpstreamLDAP.TestUserDirectGroupsDNs,
 		},
+		{
+			name:      "ldap using posix groups by using the UserAttributeForFilter option to adjust the group search filter behavior",
+			maybeSkip: skipLDAPTests,
+			createIDP: func(t *testing.T) string {
+				idp, _ := createLDAPIdentityProvider(t, func(spec *idpv1alpha1.LDAPIdentityProviderSpec) {
+					spec.GroupSearch.Filter = "&(objectClass=posixGroup)(memberUid={})"
+					spec.GroupSearch.UserAttributeForFilter = "uid"
+					spec.GroupSearch.Attributes.GroupName = "cn"
+				})
+				return idp.Name
+			},
+			requestAuthorization: func(t *testing.T, _, downstreamAuthorizeURL, _, _, _ string, httpClient *http.Client) {
+				requestAuthorizationUsingCLIPasswordFlow(t,
+					downstreamAuthorizeURL,
+					env.SupervisorUpstreamLDAP.TestUserMailAttributeValue, // username to present to server during login
+					env.SupervisorUpstreamLDAP.TestUserPassword,           // password to present to server during login
+					httpClient,
+					false,
+				)
+			},
+			// the ID token Subject should be the Host URL plus the value pulled from the requested UserSearch.Attributes.UID attribute
+			wantDownstreamIDTokenSubjectToMatch: "^" + regexp.QuoteMeta(
+				"ldaps://"+env.SupervisorUpstreamLDAP.Host+
+					"?base="+url.QueryEscape(env.SupervisorUpstreamLDAP.UserSearchBase)+
+					"&sub="+base64.RawURLEncoding.EncodeToString([]byte(env.SupervisorUpstreamLDAP.TestUserUniqueIDAttributeValue)),
+			) + "$",
+			// the ID token Username should have been pulled from the requested UserSearch.Attributes.Username attribute
+			wantDownstreamIDTokenUsernameToMatch: func(_ string) string {
+				return "^" + regexp.QuoteMeta(env.SupervisorUpstreamLDAP.TestUserMailAttributeValue) + "$"
+			},
+			wantDownstreamIDTokenGroups: env.SupervisorUpstreamLDAP.TestUserDirectPosixGroupsCNs,
+		},
 		{
 			name:      "ldap without requesting username and groups scope gets them anyway for pinniped-cli for backwards compatibility with old CLIs",
 			maybeSkip: skipLDAPTests,
diff --git a/test/testlib/env.go b/test/testlib/env.go
index fd79fd85..387d8a08 100644
--- a/test/testlib/env.go
+++ b/test/testlib/env.go
@@ -1,4 +1,4 @@
-// Copyright 2020-2022 the Pinniped contributors. All Rights Reserved.
+// Copyright 2020-2023 the Pinniped contributors. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
 package testlib
@@ -98,6 +98,7 @@ type TestLDAPUpstream struct {
 	TestUserUniqueIDAttributeName                   string   `json:"testUserUniqueIDAttributeName"`
 	TestUserUniqueIDAttributeValue                  string   `json:"testUserUniqueIDAttributeValue"`
 	TestUserDirectGroupsCNs                         []string `json:"testUserDirectGroupsCNs"`
+	TestUserDirectPosixGroupsCNs                    []string `json:"testUserDirectPosixGroupsCNs"`
 	TestUserDirectGroupsDNs                         []string `json:"testUserDirectGroupsDNs"` //nolint:revive // this is "distinguished names", not "DNS"
 	TestUserSAMAccountNameValue                     string   `json:"testUserSAMAccountNameValue"`
 	TestUserPrincipalNameValue                      string   `json:"testUserPrincipalNameValue"`
@@ -267,6 +268,7 @@ func loadEnvVars(t *testing.T, result *TestEnv) {
 		TestUserMailAttributeName:      needEnv(t, "PINNIPED_TEST_LDAP_USER_EMAIL_ATTRIBUTE_NAME"),
 		TestUserMailAttributeValue:     needEnv(t, "PINNIPED_TEST_LDAP_USER_EMAIL_ATTRIBUTE_VALUE"),
 		TestUserDirectGroupsCNs:        filterEmpty(strings.Split(needEnv(t, "PINNIPED_TEST_LDAP_EXPECTED_DIRECT_GROUPS_CN"), ";")),
+		TestUserDirectPosixGroupsCNs:   filterEmpty(strings.Split(needEnv(t, "PINNIPED_TEST_LDAP_EXPECTED_DIRECT_POSIX_GROUPS_CN"), ";")),
 		TestUserDirectGroupsDNs:        filterEmpty(strings.Split(needEnv(t, "PINNIPED_TEST_LDAP_EXPECTED_DIRECT_GROUPS_DN"), ";")),
 		TestUserPassword:               needEnv(t, "PINNIPED_TEST_LDAP_USER_PASSWORD"),
 	}