diff --git a/test/t/lang.rb b/test/t/lang.rb
new file mode 100755
index 000000000..23b92771a
--- /dev/null
+++ b/test/t/lang.rb
@@ -0,0 +1,73 @@
+# The aim of these tests is  to detect pitfall for optimized VM.
+
+# Test for or/and
+#
+# You may think instruction fusion(OP_EQ and OP_JMPIF) for avoiding
+# generate intermedicate boolean value.
+# But and/or is pitfall for this fusioning.
+#
+# For example. Folloging mruby code
+#   if i > 0 and i < 10 then
+#
+# compilies to RITE bitecode
+#
+#    1 000 OP_LOADI      R1      0               ; R1:i
+#    2 001 OP_MOVE       R2      R1              ; R1:i
+#    2 002 OP_LOADI      R3      0
+#    2 003 OP_GT R2      :>      1
+#    2 004 OP_JMPNOT     R2      008
+#    2 005 OP_MOVE       R2      R1              ; R1:i
+#    2 006 OP_LOADI      R3      10
+#    2 007 OP_LT R2      :<      1
+#    2 008 OP_JMPNOT     R2      (The address of end of then part)
+#
+# When the instruction fusion the OP_GT and OP_JMPNOT you fell into the pitfalls.
+# The deleted intermedicate boolean value is used in OP_JMPNOT (address 008).
+
+assert('and', '11.2.3') do
+  a = 1
+  if a > 0 and a < 10 then
+    b = 1
+  else
+    b = 0
+  end
+  assert_equal 1, b
+
+  if a < 0 and a < 10 then
+    b = 1
+  else
+    b = 0
+  end
+  assert_equal 0, b
+
+  if a < 0 and a > 10 then
+    b = 1
+  else
+    b = 0
+  end
+  assert_equal 0, b
+end
+
+assert('or','11.2.4') do
+  a = 1
+  if a > 0 or a < 10 then
+    b = 1
+  else
+    b = 0
+  end
+  assert_equal 1, b
+
+  if a < 0 or a < 10 then
+    b = 1
+  else
+    b = 0
+  end
+  assert_equal 1, b
+
+  if a < 0 or a > 10 then
+    b = 1
+  else
+    b = 0
+  end
+  assert_equal 0, b
+end