--- a/config/rules.mk
+++ b/config/rules.mk
@@ -855,30 +855,30 @@ mk_libname = $(basename lib$(notdir $1))
 src_libdep = $(call mk_libname,$1): $1 $$(call mkdir_deps,$$(MDDEPDIR))
 $(foreach f,$(RSSRCS),$(eval $(call src_libdep,$(f))))
 
 $(OBJS) $(HOST_OBJS) $(PROGOBJS) $(HOST_PROGOBJS): $(GLOBAL_DEPS)
 
 # Rules for building native targets must come first because of the host_ prefix
 $(HOST_COBJS):
 	$(REPORT_BUILD)
-	$(ELOG) $(HOST_CC) $(HOST_OUTOPTION)$@ -c $(HOST_CFLAGS) $(INCLUDES) $(NSPR_CFLAGS) $(_VPATH_SRCS)
+	$(ELOG) $(HOST_CC) $(HOST_OUTOPTION)$@ -c $(HOST_CPPFLAGS) $(HOST_CFLAGS) $(INCLUDES) $(NSPR_CFLAGS) $(_VPATH_SRCS)
 
 $(HOST_CPPOBJS):
 	$(REPORT_BUILD)
 	$(call BUILDSTATUS,OBJECT_FILE $@)
-	$(ELOG) $(HOST_CXX) $(HOST_OUTOPTION)$@ -c $(HOST_CXXFLAGS) $(INCLUDES) $(NSPR_CFLAGS) $(_VPATH_SRCS)
+	$(ELOG) $(HOST_CXX) $(HOST_OUTOPTION)$@ -c $(HOST_CPPFLAGS) $(HOST_CXXFLAGS) $(INCLUDES) $(NSPR_CFLAGS) $(_VPATH_SRCS)
 
 $(HOST_CMOBJS):
 	$(REPORT_BUILD)
-	$(ELOG) $(HOST_CC) $(HOST_OUTOPTION)$@ -c $(HOST_CFLAGS) $(HOST_CMFLAGS) $(INCLUDES) $(NSPR_CFLAGS) $(_VPATH_SRCS)
+	$(ELOG) $(HOST_CC) $(HOST_OUTOPTION)$@ -c $(HOST_CPPFLAGS) $(HOST_CFLAGS) $(HOST_CMFLAGS) $(INCLUDES) $(NSPR_CFLAGS) $(_VPATH_SRCS)
 
 $(HOST_CMMOBJS):
 	$(REPORT_BUILD)
-	$(ELOG) $(HOST_CXX) $(HOST_OUTOPTION)$@ -c $(HOST_CXXFLAGS) $(HOST_CMMFLAGS) $(INCLUDES) $(NSPR_CFLAGS) $(_VPATH_SRCS)
+	$(ELOG) $(HOST_CXX) $(HOST_OUTOPTION)$@ -c $(HOST_CPPFLAGS) $(HOST_CXXFLAGS) $(HOST_CMMFLAGS) $(INCLUDES) $(NSPR_CFLAGS) $(_VPATH_SRCS)
 
 $(COBJS):
 	$(REPORT_BUILD)
 	$(ELOG) $(CC) $(OUTOPTION)$@ -c $(COMPILE_CFLAGS) $($(notdir $<)_FLAGS) $(TARGET_LOCAL_INCLUDES) $(_VPATH_SRCS)
 
 # DEFINES and ACDEFINES are needed here to enable conditional compilation of Q_OBJECTs:
 # 'moc' only knows about #defines it gets on the command line (-D...), not in
 # included headers like mozilla-config.h

--- a/js/src/old-configure.in
+++ b/js/src/old-configure.in
@@ -2694,16 +2694,17 @@ AC_SUBST(OS_CPPFLAGS)
 AC_SUBST(OS_COMPILE_CFLAGS)
 AC_SUBST(OS_COMPILE_CXXFLAGS)
 AC_SUBST(OS_LDFLAGS)
 AC_SUBST(OS_LIBS)
 
 AC_SUBST(HOST_CC)
 AC_SUBST(HOST_CXX)
 AC_SUBST(HOST_CFLAGS)
+AC_SUBST(HOST_CPPFLAGS)
 AC_SUBST(HOST_CXXFLAGS)
 AC_SUBST(HOST_LDFLAGS)
 AC_SUBST(HOST_OPTIMIZE_FLAGS)
 AC_SUBST(HOST_AR)
 AC_SUBST(HOST_AR_FLAGS)
 AC_SUBST(HOST_LD)
 AC_SUBST(HOST_RANLIB)
 AC_SUBST(HOST_BIN_SUFFIX)

--- a/old-configure.in
+++ b/old-configure.in
@@ -7474,16 +7474,17 @@ AC_SUBST(OS_COMPILE_CFLAGS)
 AC_SUBST(OS_COMPILE_CXXFLAGS)
 AC_SUBST(OS_LDFLAGS)
 AC_SUBST(OS_LIBS)
 AC_SUBST(WCHAR_CFLAGS)
 
 AC_SUBST(HOST_CC)
 AC_SUBST(HOST_CXX)
 AC_SUBST(HOST_CFLAGS)
+AC_SUBST(HOST_CPPFLAGS)
 AC_SUBST(HOST_CXXFLAGS)
 AC_SUBST(HOST_LDFLAGS)
 AC_SUBST(HOST_OPTIMIZE_FLAGS)
 AC_SUBST(HOST_AR)
 AC_SUBST(HOST_AR_FLAGS)
 AC_SUBST(HOST_LD)
 AC_SUBST(HOST_RANLIB)
 AC_SUBST(HOST_BIN_SUFFIX)
@@ -7843,16 +7844,17 @@ export ARFLAGS
 export CPPFLAGS
 export CFLAGS
 export CXXFLAGS
 export LDFLAGS
 export RUSTFLAGS
 export HOST_CC
 export HOST_CXX
 export HOST_CFLAGS
+export HOST_CPPFLAGS
 export HOST_CXXFLAGS
 export HOST_LDFLAGS
 
 if ! test -e js; then
     mkdir js
 fi
 
 AC_OUTPUT_SUBDIRS(js/src,$cache_file)