--- a/js/moz.configure
+++ b/js/moz.configure
@@ -1104,7 +1104,7 @@ set_define(
 # ======================================================
 system_lib_option("--with-system-icu", help="Use system ICU")
 
-system_icu = pkg_check_modules("MOZ_ICU", "icu-i18n >= 73.1", when="--with-system-icu")
+system_icu = pkg_check_modules("MOZ_ICU", "icu-uc icu-i18n >= 73.1", when="--with-system-icu")
 
 
 @depends("--with-system-icu")
