diff --git a/src/driver/ptyc_driver_ctx.c b/src/driver/ptyc_driver_ctx.c
index cd038ee..70d44f5 100644
--- a/src/driver/ptyc_driver_ctx.c
+++ b/src/driver/ptyc_driver_ctx.c
@@ -271,8 +271,8 @@ void ptyc_free_driver_ctx(struct ptyc_driver_ctx * ctx)
 	uintptr_t			addr;
 
 	if (ctx) {
-		addr = (uintptr_t)ctx - offsetof(struct ptyc_driver_ctx_alloc,ctx);
-		addr = addr - offsetof(struct ptyc_driver_ctx_impl,ctx);
+		addr = (uintptr_t)ctx - offsetof(struct ptyc_driver_ctx_impl,ctx);
+		addr = addr - offsetof(struct ptyc_driver_ctx_alloc,ctx);
 		ictx = (struct ptyc_driver_ctx_alloc *)addr;
 		ptyc_free_driver_ctx_impl(ictx);
 	}