diff --git a/examples/sample.source.PKIX1/Makefile b/examples/sample.source.PKIX1/Makefile
index c4d3eac..b97d035 100644
--- a/examples/sample.source.PKIX1/Makefile
+++ b/examples/sample.source.PKIX1/Makefile
@@ -296,9 +296,9 @@
 ASN_MODULE_SOURCES+=constr_SEQUENCE.c
 ASN_MODULE_HEADERS+=constr_SEQUENCE_OF.h
 ASN_MODULE_SOURCES+=constr_SEQUENCE_OF.c
+ASN_MODULE_HEADERS+=constr_SET_OF.h
 ASN_MODULE_HEADERS+=constr_SET.h
 ASN_MODULE_SOURCES+=constr_SET.c
-ASN_MODULE_HEADERS+=constr_SET_OF.h
 ASN_MODULE_SOURCES+=constr_SET_OF.c
 ASN_MODULE_HEADERS+=asn_application.h
 ASN_MODULE_HEADERS+=asn_internal.h