diff --git a/benchmark/vm_ivar_embedded_obj_init.yml b/benchmark/vm_ivar_embedded_obj_init.yml
index eed6d4c0b9..74fe20a630 100644
--- a/benchmark/vm_ivar_embedded_obj_init.yml
+++ b/benchmark/vm_ivar_embedded_obj_init.yml
@@ -1,12 +1,14 @@
 prelude: |
   class C
-    def initialize
+    def set_ivars
       @a = nil
       @b = nil
       @c = nil
     end
   end
+
+  c = C.new
 benchmark:
   vm_ivar_embedded_obj_init: |
-    C.new
+    c.set_ivars
 loop_count: 30000000
diff --git a/benchmark/vm_ivar_extended_obj_init.yml b/benchmark/vm_ivar_extended_obj_init.yml
index 994e9e6c49..f054bab282 100644
--- a/benchmark/vm_ivar_extended_obj_init.yml
+++ b/benchmark/vm_ivar_extended_obj_init.yml
@@ -1,6 +1,6 @@
 prelude: |
   class C
-    def initialize
+    def set_ivars
       @a = nil
       @b = nil
       @c = nil
@@ -8,7 +8,9 @@ prelude: |
       @e = nil
     end
   end
+
+  c = C.new
 benchmark:
   vm_ivar_extended_obj_init: |
-    C.new
+    c.set_ivars
 loop_count: 30000000
diff --git a/benchmark/vm_ivar_set_subclass.yml b/benchmark/vm_ivar_set_subclass.yml
index 2653d36ded..bc8bf5bf6b 100644
--- a/benchmark/vm_ivar_set_subclass.yml
+++ b/benchmark/vm_ivar_set_subclass.yml
@@ -1,6 +1,6 @@
 prelude: |
   class A
-    def initialize
+    def set_ivars
       @a = nil
       @b = nil
       @c = nil
@@ -10,8 +10,11 @@ prelude: |
   end
   class B < A; end
   class C < A; end
+
+  b = B.new
+  c = C.new
 benchmark:
   vm_ivar_init_subclass: |
-    B.new
-    C.new
+    b.set_ivars
+    c.set_ivars
 loop_count: 3000000