diff --git a/tests/phpunit/includes/functions.php b/tests/phpunit/includes/functions.php
index e8d30cb0c1..b7b9f87397 100644
--- a/tests/phpunit/includes/functions.php
+++ b/tests/phpunit/includes/functions.php
@@ -102,4 +102,16 @@ function _wp_die_handler_txt( $message, $title, $args ) {
 			echo "\t $k : $v\n";
 		}
 	}
-}
\ No newline at end of file
+}
+
+/**
+ * Set a permalink structure.
+ *
+ * Hooked as a callback to the 'populate_options' action, we use this function to set a permalink structure during
+ * `wp_install()`, so that WP doesn't attempt to do a time-consuming remote request.
+ *
+ * @since 4.2.0
+ */
+function _set_default_permalink_structure_for_tests() {
+	update_option( 'permalink_structure', '/%year%/%monthnum%/%day%/%postname%/' );
+}
diff --git a/tests/phpunit/includes/install.php b/tests/phpunit/includes/install.php
index ff4090e55a..592e3808d6 100644
--- a/tests/phpunit/includes/install.php
+++ b/tests/phpunit/includes/install.php
@@ -44,8 +44,17 @@ foreach ( $wpdb->tables( 'ms_global' ) as $table => $prefixed_table ) {
 		$wpdb->$table = $prefixed_table;
 }
 
+// Prefill a permalink structure so that WP doesn't try to determine one itself.
+add_action( 'populate_options', '_set_default_permalink_structure_for_tests' );
+
 wp_install( WP_TESTS_TITLE, 'admin', WP_TESTS_EMAIL, true, null, 'password' );
 
+// Delete dummy permalink structure, as prefilled above.
+if ( ! is_multisite() ) {
+	delete_option( 'permalink_structure' );
+}
+remove_action( 'populate_options', '_set_default_permalink_structure_for_tests' );
+
 if ( $multisite ) {
 	echo "Installing network..." . PHP_EOL;