diff --git a/sys/modules/cxgb/Makefile b/sys/modules/cxgb/Makefile
index 9ed1f24932d6..ed43eae3dd7c 100644
--- a/sys/modules/cxgb/Makefile
+++ b/sys/modules/cxgb/Makefile
@@ -2,7 +2,15 @@
 SUBDIR= cxgb
 SUBDIR+= toecore
 SUBDIR+= tom
-SUBDIR+= iw_cxgb
+SUBDIR+= ${_iw_cxgb}
 SUBDIR+= cxgb_t3fw
 
+.if ${MACHINE_ARCH} == "i386"
+_iw_cxgb = iw_cxgb
+.endif
+
+.if ${MACHINE_ARCH} == "amd64"
+_iw_cxgb = iw_cxgb
+.endif
+
 .include <bsd.subdir.mk>