diff --git a/src/vim9compile.c b/src/vim9compile.c
index 2b65ff9..77945fb 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -2056,6 +2056,8 @@
 
 	if (generate_LOAD(cctx, ISN_LOAD, 0, NULL, lhs->lhs_type) == FAIL)
 	    return FAIL;
+	if (cl->class_flags & CLASS_INTERFACE)
+	    return generate_GET_ITF_MEMBER(cctx, cl, lhs->lhs_member_idx, type);
 	return generate_GET_OBJ_MEMBER(cctx, lhs->lhs_member_idx, type);
     }