diff --git a/shared/nm-glib-aux/nm-str-buf.h b/shared/nm-glib-aux/nm-str-buf.h
index afbb001ca1..4c015aa43c 100644
--- a/shared/nm-glib-aux/nm-str-buf.h
+++ b/shared/nm-glib-aux/nm-str-buf.h
@@ -13,7 +13,7 @@
 typedef struct _NMStrBuf {
 	char *_str;
 	union {
-		const gsize len;
+		/*const*/ gsize len;
 		gsize _len;
 	};
 	gsize _allocated;