diff --git a/src/vim9expr.c b/src/vim9expr.c
index 6131f9f..95c6d7d 100644
--- a/src/vim9expr.c
+++ b/src/vim9expr.c
@@ -364,6 +364,8 @@
 		}
 
 		*arg = name_end;
+		if (cl->class_flags & CLASS_INTERFACE)
+		    return generate_GET_ITF_MEMBER(cctx, cl, i, m->ocm_type);
 		return generate_GET_OBJ_MEMBER(cctx, i, m->ocm_type);
 	    }
 	}