divide and conquer; fight with 4700 files of RRC

diff --git a/examples/sample.source.PKIX1/Makefile b/examples/sample.source.PKIX1/Makefile
index 8f902b2..2038796 100644
--- a/examples/sample.source.PKIX1/Makefile
+++ b/examples/sample.source.PKIX1/Makefile
@@ -392,6 +392,7 @@
 	@echo ================
 
 distclean: clean
-	rm -f $(ASN_MODULE_SOURCES) $(ASN_MODULE_HEADERS)
+	rm -f $(ASN_MODULE_SOURCES)
+	rm -f $(ASN_MODULE_HEADERS)
 	rm -f $(ASN_CONVERTER_SOURCES) $(ASN_CONVERTER_HEADERS)
 	rm -f Makefile.am.sample