diff --git a/src/py65/devices/mpu65c02.py b/src/py65/devices/mpu65c02.py
index 6ef2e5c..7f4cda7 100644
--- a/src/py65/devices/mpu65c02.py
+++ b/src/py65/devices/mpu65c02.py
@@ -43,6 +43,11 @@ class MPU(NMOS6502):
         self.memory[address] = m & ~self.a
 
     # instructions
+    
+    @instruction(name="ORA", mode="zpi", cycles=5)
+    def i12(self):
+        self.opORA(self.IndirectXAddr)
+        self.pc += 1
 
     @instruction(name="PHY", mode="imp", cycles=3)
     def i5a(self):
diff --git a/src/py65/tests/devices/test_mpu65c02.py b/src/py65/tests/devices/test_mpu65c02.py
index 9138aab..16dea3f 100644
--- a/src/py65/tests/devices/test_mpu65c02.py
+++ b/src/py65/tests/devices/test_mpu65c02.py
@@ -38,6 +38,33 @@ class MPUTests(unittest.TestCase, Common6502Tests):
         self.assertEquals(mpu.ZERO, mpu.flags & mpu.ZERO)
         self.assertEquals(0, mpu.flags & mpu.NEGATIVE)
 
+    # ORA Zero Page, Indirect
+    
+    def test_ora_zp_indirect_x_zeroes_or_zeros_sets_z_flag(self):
+        mpu = self._make_mpu()
+        mpu.flags &= ~(mpu.ZERO)
+        mpu.a = 0x00
+        self._write(mpu.memory, 0x0000, (0x12, 0x10)) #=> ORA ($0010)
+        self._write(mpu.memory, 0x0010, (0xCD, 0xAB)) #=> Vector to $ABCD
+        mpu.memory[0xABCD] = 0x00
+        mpu.step()
+        self.assertEquals(0x0002, mpu.pc)
+        self.assertEquals(0x00, mpu.a)
+        self.assertEquals(mpu.ZERO, mpu.flags & mpu.ZERO)
+  
+    def test_ora_zp_indirect_x_turns_bits_on_sets_n_flag(self):
+        mpu = self._make_mpu()
+        mpu.flags &= ~(mpu.NEGATIVE)
+        mpu.a = 0x03
+        self._write(mpu.memory, 0x0000, (0x12, 0x10)) #=> ORA ($0010)
+        self._write(mpu.memory, 0x0010, (0xCD, 0xAB)) #=> Vector to $ABCD
+        mpu.memory[0xABCD] = 0x82
+        mpu.step()
+        self.assertEquals(0x0002, mpu.pc)
+        self.assertEquals(0x83, mpu.a)
+        self.assertEquals(mpu.NEGATIVE, mpu.flags & mpu.NEGATIVE)
+        self.assertEquals(0, mpu.flags & mpu.ZERO)
+
     # PHX
   
     def test_phx_pushes_x_and_updates_sp(self):