diff --git a/cypress/tests/functional/CustomLocale.cy.js b/cypress/tests/functional/CustomLocale.cy.js
index 3a421ee..625cc54 100644
--- a/cypress/tests/functional/CustomLocale.cy.js
+++ b/cypress/tests/functional/CustomLocale.cy.js
@@ -23,7 +23,7 @@ describe('Custom Locale plugin tests', function() {
 
 		// FIXME: The new settings tab handler doesn't jump right to the correct tab.
 		cy.get('button#customLocale-button').click();
-		cy.get('a[href*=en_US]:contains("Edit")').click();
+		cy.get('a[href*=en]:contains("Edit")').click();
 		cy.wait(1000); // Form init
 		cy.get('input.pkpSearch__input').type('user.affiliation');
 		cy.get('button.pkpButton:contains("Search")').click();
@@ -38,6 +38,6 @@ describe('Custom Locale plugin tests', function() {
 		cy.get('.app__userNav a:contains("Edit Profile")').click({ force: true }); // Force workaround for lack of .hover() in Cypress
 		cy.wait(5000); // Delay to ensure cache refresh
 		cy.get('a:contains("Contact")').click();
-		cy.get('label[for^="affiliation-en_US"]:contains("Floog Bleem")');
+		cy.get('label[for^="affiliation-en"]:contains("Floog Bleem")');
 	});
 });
diff --git a/locale/ar_IQ/locale.po b/locale/ar/locale.po
similarity index 100%
rename from locale/ar_IQ/locale.po
rename to locale/ar/locale.po
diff --git a/locale/bg_BG/locale.po b/locale/bg/locale.po
similarity index 100%
rename from locale/bg_BG/locale.po
rename to locale/bg/locale.po
diff --git a/locale/bs_BA/locale.po b/locale/bs/locale.po
similarity index 100%
rename from locale/bs_BA/locale.po
rename to locale/bs/locale.po
diff --git a/locale/ca_ES/locale.po b/locale/ca/locale.po
similarity index 100%
rename from locale/ca_ES/locale.po
rename to locale/ca/locale.po
diff --git a/locale/cs_CZ/locale.po b/locale/cs/locale.po
similarity index 100%
rename from locale/cs_CZ/locale.po
rename to locale/cs/locale.po
diff --git a/locale/da_DK/locale.po b/locale/da/locale.po
similarity index 100%
rename from locale/da_DK/locale.po
rename to locale/da/locale.po
diff --git a/locale/de_DE/locale.po b/locale/de/locale.po
similarity index 100%
rename from locale/de_DE/locale.po
rename to locale/de/locale.po
diff --git a/locale/el_GR/locale.po b/locale/el/locale.po
similarity index 100%
rename from locale/el_GR/locale.po
rename to locale/el/locale.po
diff --git a/locale/en_US/locale.po b/locale/en/locale.po
similarity index 100%
rename from locale/en_US/locale.po
rename to locale/en/locale.po
diff --git a/locale/es_ES/locale.po b/locale/es/locale.po
similarity index 100%
rename from locale/es_ES/locale.po
rename to locale/es/locale.po
diff --git a/locale/fi_FI/locale.po b/locale/fi/locale.po
similarity index 100%
rename from locale/fi_FI/locale.po
rename to locale/fi/locale.po
diff --git a/locale/gl_ES/locale.po b/locale/gl/locale.po
similarity index 100%
rename from locale/gl_ES/locale.po
rename to locale/gl/locale.po
diff --git a/locale/hy_AM/locale.po b/locale/hy/locale.po
similarity index 100%
rename from locale/hy_AM/locale.po
rename to locale/hy/locale.po
diff --git a/locale/id_ID/locale.po b/locale/id/locale.po
similarity index 100%
rename from locale/id_ID/locale.po
rename to locale/id/locale.po
diff --git a/locale/it_IT/locale.po b/locale/it/locale.po
similarity index 100%
rename from locale/it_IT/locale.po
rename to locale/it/locale.po
diff --git a/locale/ka_GE/locale.po b/locale/ka/locale.po
similarity index 100%
rename from locale/ka_GE/locale.po
rename to locale/ka/locale.po
diff --git a/locale/mk_MK/locale.po b/locale/mk/locale.po
similarity index 100%
rename from locale/mk_MK/locale.po
rename to locale/mk/locale.po
diff --git a/locale/nb_NO/locale.po b/locale/nb/locale.po
similarity index 100%
rename from locale/nb_NO/locale.po
rename to locale/nb/locale.po
diff --git a/locale/ru_RU/locale.po b/locale/ru/locale.po
similarity index 100%
rename from locale/ru_RU/locale.po
rename to locale/ru/locale.po
diff --git a/locale/sl_SI/locale.po b/locale/sl/locale.po
similarity index 100%
rename from locale/sl_SI/locale.po
rename to locale/sl/locale.po
diff --git a/locale/sv_SE/locale.po b/locale/sv/locale.po
similarity index 100%
rename from locale/sv_SE/locale.po
rename to locale/sv/locale.po
diff --git a/locale/tr_TR/locale.po b/locale/tr/locale.po
similarity index 100%
rename from locale/tr_TR/locale.po
rename to locale/tr/locale.po
diff --git a/locale/vi_VN/locale.po b/locale/vi/locale.po
similarity index 100%
rename from locale/vi_VN/locale.po
rename to locale/vi/locale.po