diff --git a/ChangeLog b/ChangeLog
index 82374795fc..dc5d27b846 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Jul  4 09:38:52 2015  Eric Wong  <e@80x24.org>
+
+	* vm.c (rb_vm_mark): reduce branches for always-set VM fields
+	  (rb_vm_add_root_module): ditto
+
 Fri Jul 03 20:05:10 2015  Koichi Sasada  <ko1@atdot.net>
 
 	* method.h: introduce rb_callable_method_entry_t to remove
diff --git a/vm.c b/vm.c
index 06719ad55b..36d5c8b42a 100644
--- a/vm.c
+++ b/vm.c
@@ -1816,17 +1816,17 @@ rb_vm_mark(void *ptr)
 	list_for_each(&vm->living_threads, th, vmlt_node) {
 	    rb_gc_mark(th->self);
 	}
-	RUBY_MARK_UNLESS_NULL(vm->thgroup_default);
-	RUBY_MARK_UNLESS_NULL(vm->mark_object_ary);
-	RUBY_MARK_UNLESS_NULL(vm->load_path);
-	RUBY_MARK_UNLESS_NULL(vm->load_path_snapshot);
+	rb_gc_mark(vm->thgroup_default);
+	rb_gc_mark(vm->mark_object_ary);
+	rb_gc_mark(vm->load_path);
+	rb_gc_mark(vm->load_path_snapshot);
 	RUBY_MARK_UNLESS_NULL(vm->load_path_check_cache);
-	RUBY_MARK_UNLESS_NULL(vm->expanded_load_path);
-	RUBY_MARK_UNLESS_NULL(vm->loaded_features);
-	RUBY_MARK_UNLESS_NULL(vm->loaded_features_snapshot);
-	RUBY_MARK_UNLESS_NULL(vm->top_self);
+	rb_gc_mark(vm->expanded_load_path);
+	rb_gc_mark(vm->loaded_features);
+	rb_gc_mark(vm->loaded_features_snapshot);
+	rb_gc_mark(vm->top_self);
 	RUBY_MARK_UNLESS_NULL(vm->coverages);
-	RUBY_MARK_UNLESS_NULL(vm->defined_module_hash);
+	rb_gc_mark(vm->defined_module_hash);
 
 	if (vm->loading_table) {
 	    rb_mark_tbl(vm->loading_table);
@@ -1858,9 +1858,9 @@ int
 rb_vm_add_root_module(ID id, VALUE module)
 {
     rb_vm_t *vm = GET_VM();
-    if (vm->defined_module_hash) {
-	rb_hash_aset(vm->defined_module_hash, ID2SYM(id), module);
-    }
+
+    rb_hash_aset(vm->defined_module_hash, ID2SYM(id), module);
+
     return TRUE;
 }