--- dovecot-2.3.21.1/m4/want_icu.m4.orig	2024-10-27 21:48:06.430987100 +0800
+++ dovecot-2.3.21.1/m4/want_icu.m4	2024-10-27 21:48:28.717847700 +0800
@@ -1,7 +1,7 @@
 AC_DEFUN([DOVECOT_WANT_ICU], [
   if test "$want_icu" != "no"; then
     if test "$PKG_CONFIG" != "" && $PKG_CONFIG --exists icu-i18n 2>/dev/null; then
-      PKG_CHECK_MODULES(LIBICU, icu-i18n)
+      PKG_CHECK_MODULES(LIBICU, icu-i18n icu-uc)
       have_icu=yes
       AC_DEFINE(HAVE_LIBICU,, [Define if you want ICU normalization support for FTS])
     elif test "$want_icu" = "yes"; then