diff --git a/src/vim9expr.c b/src/vim9expr.c
index 7a32974..7a089e9 100644
--- a/src/vim9expr.c
+++ b/src/vim9expr.c
@@ -185,6 +185,18 @@
 	    // a copy is made so the member type is no longer declared
 	    if (typep->type_decl->tt_type == VAR_LIST)
 		typep->type_decl = &t_list_any;
+
+	    // a copy is made, the composite is no longer "const"
+	    if (typep->type_curr->tt_flags & TTFLAG_CONST)
+	    {
+		type_T *type = copy_type(typep->type_curr, cctx->ctx_type_list);
+
+		if (type != typep->type_curr)  // did get a copy
+		{
+		    type->tt_flags &= ~(TTFLAG_CONST | TTFLAG_STATIC);
+		    typep->type_curr = type;
+		}
+	    }
 	}
 	else
 	{