diff --git a/src/vendorcode/siemens/Makefile.inc b/src/vendorcode/siemens/Makefile.inc
index 88fd1c3911..342375b416 100644
--- a/src/vendorcode/siemens/Makefile.inc
+++ b/src/vendorcode/siemens/Makefile.inc
@@ -1,3 +1,5 @@
 ## SPDX-License-Identifier: GPL-2.0-only
 
 subdirs-$(CONFIG_USE_SIEMENS_HWILIB) += hwilib
+
+CPPFLAGS_common += -I$(src)/vendorcode/siemens/hwilib
diff --git a/src/vendorcode/siemens/hwilib/Makefile.inc b/src/vendorcode/siemens/hwilib/Makefile.inc
index 2456db2427..9a5d4be342 100644
--- a/src/vendorcode/siemens/hwilib/Makefile.inc
+++ b/src/vendorcode/siemens/hwilib/Makefile.inc
@@ -1,6 +1,4 @@
 ## SPDX-License-Identifier: GPL-2.0-only
 
-CFLAGS_x86_32 += -Isrc/vendorcode/siemens/hwilib
-
 romstage-y += hwilib.c
 ramstage-y += hwilib.c