Rename ASN_MODULE_{SOURCES,HEADERS} => ASN_MODULE_{SRCS,HDRS}
diff --git a/examples/sample.source.ULP/Makefile b/examples/sample.source.ULP/Makefile
index e666e3e..23ee903 100644
--- a/examples/sample.source.ULP/Makefile
+++ b/examples/sample.source.ULP/Makefile
@@ -101,7 +101,7 @@
 	@if [ -f WIP ]; then cat WIP; sleep 2; fi
 
 distclean: clean
-	rm -f $(ASN_MODULE_SOURCES)
-	rm -f $(ASN_MODULE_HEADERS)
-	rm -f $(ASN_PROGRAM_SOURCES) $(ASN_PROGRAM_HEADERS)
+	rm -f $(ASN_MODULE_SRCS)
+	rm -f $(ASN_MODULE_HDRS)
+	rm -f $(ASN_PROGRAM_SRCS) $(ASN_PROGRAM_HDRS)
 	rm -f Makefile.am.example