simpler makefile generation
diff --git a/examples/sample.source.MHEG5/Makefile b/examples/sample.source.MHEG5/Makefile
index bcafe0c..432aebe 100644
--- a/examples/sample.source.MHEG5/Makefile
+++ b/examples/sample.source.MHEG5/Makefile
@@ -477,10 +477,10 @@
 	make
 
 regen-makefile:
-	ASN1CMDOPTS="-fcompound-names" \
-	ASN1MODULES="../ISO13522-MHEG-5.asn" \
-	ASN1PDU=InterchangedObject \
-	PROGNAME=mheg5dump \
+	ASN_CMDOPTS="-fcompound-names" \
+	ASN_MODULES="../ISO13522-MHEG-5.asn" \
+	ASN_PDU=InterchangedObject \
+	ASN_PROGRAM=mheg5dump \
 	CFLAGS="" \
 	../sample.makefile.regen