diff --git a/ext/tk/tcltklib.c b/ext/tk/tcltklib.c
index 40d546ea9d..f082d3922f 100644
--- a/ext/tk/tcltklib.c
+++ b/ext/tk/tcltklib.c
@@ -6374,10 +6374,11 @@ ip_create_slave_core(interp, argc, argv)
     VALUE *argv;
 {
     struct tcltkip *master = get_ip(interp);
-    struct tcltkip *slave = ALLOC(struct tcltkip);
+    struct tcltkip *slave;
     /* struct tcltkip *slave = RbTk_ALLOC_N(struct tcltkip, 1); */
     VALUE safemode;
     VALUE name;
+    VALUE new_ip;
     int safe;
     int thr_crit_bup;
     Tk_Window mainWin;
@@ -6416,6 +6417,8 @@ ip_create_slave_core(interp, argc, argv)
     }
 #endif
 
+    new_ip = TypedData_Make_Struct(CLASS_OF(interp), struct tcltkip,
+				   &tcltkip_type, slave);
     /* create slave-ip */
 #ifdef RUBY_USE_NATIVE_THREAD
     /* slave->tk_thread_id = 0; */
@@ -6475,7 +6478,7 @@ ip_create_slave_core(interp, argc, argv)
 
     rb_thread_critical = thr_crit_bup;
 
-    return TypedData_Wrap_Struct(CLASS_OF(interp), &tcltkip_type, slave);
+    return new_ip;
 }
 
 static VALUE
diff --git a/ext/tk/tkutil/tkutil.c b/ext/tk/tkutil/tkutil.c
index 6035a2a613..e0b8581759 100644
--- a/ext/tk/tkutil/tkutil.c
+++ b/ext/tk/tkutil/tkutil.c
@@ -1199,7 +1199,8 @@ allocate_cbsubst_info(struct cbsubst_info **inf_ptr)
   volatile VALUE proc, aliases;
   int idx;
 
-  inf = ALLOC(struct cbsubst_info);
+  VALUE info = TypedData_Make_Struct(cSUBST_INFO, struct cbsubst_info,
+				     &cbsubst_info_type, inf);
 
   inf->full_subst_length = 0;
 
@@ -1218,7 +1219,7 @@ allocate_cbsubst_info(struct cbsubst_info **inf_ptr)
 
   if (inf_ptr != (struct cbsubst_info **)NULL) *inf_ptr = inf;
 
-  return TypedData_Wrap_Struct(cSUBST_INFO, &cbsubst_info_type, inf);
+  return info;
 }
 
 static void
@@ -1246,7 +1247,7 @@ cbsubst_initialize(argc, argv, self)
 
     inf = cbsubst_get_ptr(rb_obj_class(self));
 
-   idx = 0;
+    idx = 0;
     for(iv_idx = 0; iv_idx < CBSUBST_TBL_MAX; iv_idx++) {
       if ( inf->ivar[iv_idx] == (ID) 0 ) continue;
       rb_ivar_set(self, inf->ivar[iv_idx], argv[idx++]);