diff -Nru orig/sysfonts/src/Makevars.ucrt patched/sysfonts/src/Makevars.ucrt
--- orig/sysfonts/src/Makevars.ucrt	2022-02-09 15:42:46.000000000 +0100
+++ patched/sysfonts/src/Makevars.ucrt	2024-03-01 14:11:57.975316900 +0100
@@ -1,2 +1,12 @@
-PKG_CPPFLAGS = -I$(R_TOOLS_SOFT)/include/freetype2
-PKG_LIBS = -lfreetype -lharfbuzz -lfreetype -lpng -lz -lbz2
+
+ifeq (,$(shell pkg-config --version 2>/dev/null))
+  PKG_CPPFLAGS = -I$(R_TOOLS_SOFT)/include/freetype2
+  LIBBROTLI = $(or $(and $(wildcard $(R_TOOLS_SOFT)/lib/libbrotlidec.a),-lbrotlidec -lbrotlicommon),)
+  PKG_LIBS = -lfreetype $(LIBBROTLI) -lharfbuzz -lfreetype -lpng -lz -lbz2
+else
+  PKG_LIBS = $(shell pkg-config --libs freetype2)
+  PKG_CPPFLAGS = $(shell pkg-config --cflags freetype2)
+
+  # work-around for freetype2 pkg-config file in Rtools43
+  PKG_CPPFLAGS += -I$(R_TOOLS_SOFT)/include/freetype2
+endif