diff -ur postgresql-10.13.orig/src/include/utils/pg_locale.h postgresql-10.13/src/include/utils/pg_locale.h
--- postgresql-10.13.orig/src/include/utils/pg_locale.h	2020-05-11 23:12:38.000000000 +0200
+++ postgresql-10.13/src/include/utils/pg_locale.h	2021-04-23 23:05:22.732461418 +0200
@@ -17,6 +17,7 @@
 #endif
 #ifdef USE_ICU
 #include <unicode/ucol.h>
+#undef bool
 #endif
 
 #include "utils/guc.h"