diff -Naur plus42-upstream-1.0.9.orig/gtk/Makefile plus42-upstream-1.0.9/gtk/Makefile
--- plus42-upstream-1.0.9.orig/gtk/Makefile	2022-06-19 14:44:32.000000000 +0200
+++ plus42-upstream-1.0.9/gtk/Makefile	2022-07-04 19:37:35.533799322 +0200
@@ -40,9 +40,10 @@
 	 -DDECIMAL_GLOBAL_EXCEPTION_FLAGS=1 \
 	 -DDECIMAL_GLOBAL_EXCEPTION_FLAGS_ACCESS_FUNCTIONS=1
 
-CXXFLAGS = $(CFLAGS) \
+CXXFLAGS := $(CFLAGS) \
 	 -fno-rtti \
-	 -D_WCHAR_T_DEFINED
+	 -D_WCHAR_T_DEFINED \
+	 ${CXXFLAGS}
 
 LIBS = gcc111libbid.a $(shell $(PKG_CONFIG) --libs gtk+-3.0)
 
@@ -121,7 +122,7 @@
 	./keymap2cc
 
 gcc111libbid.a:
-	sh ./build-intel-lib.sh
+	+sh ./build-intel-lib.sh
 	ln -s IntelRDFPMathLib20U1/TESTS/readtest.c
 
 symlinks: