diff --git a/src/bytecode.rs b/src/bytecode.rs
index 5082bf2..21185ff 100644
--- a/src/bytecode.rs
+++ b/src/bytecode.rs
@@ -79,6 +79,7 @@ impl Bytecode {
             0x6C => (Instruction::DivideInt(), 1),
             0x6D => (Instruction::DivideLong(), 1),
 
+            0x78 => (Instruction::ArithmeticShiftIntLeft(), 1),
             0x7A => (Instruction::ArithmeticShiftIntRight(), 1),
             0x7C => (Instruction::LogicalShiftIntRight(), 1),
             0x7E => (Instruction::AndInt(), 1),
@@ -324,7 +325,8 @@ pub enum Instruction {
     DivideInt()                             = 0x6C, // integer division, round toward zero and more rules
     DivideLong()                            = 0x6D, // long division
 
-    ArithmeticShiftIntRight()               = 0x7A, // shift int
+    ArithmeticShiftIntLeft()                = 0x78, // shift int left, preserve sign
+    ArithmeticShiftIntRight()               = 0x7A, // shift int right, preserve sign
     LogicalShiftIntRight()                  = 0x7C, // shift int right with zero extension
     AndInt()                                = 0x7E, // bitwise and
 
diff --git a/src/jvm.rs b/src/jvm.rs
index 1879548..108a53a 100644
--- a/src/jvm.rs
+++ b/src/jvm.rs
@@ -678,13 +678,20 @@ impl JVM {
                     wrap_stackframe_error(class, method, frame.operand_stack.push(StackValue::Int(value_0 + value_1)))?;
                 }
 
+                Instruction::ArithmeticShiftIntLeft() => {
+                    let shift = wrap_stackframe_error(class, method, frame.operand_stack.pop_int(0))? as u8 & 0b00011111;
+                    let int   = wrap_stackframe_error(class, method, frame.operand_stack.pop_int(0))?;
+
+                    // rust does arithmetic shift on singed values
+                    wrap_stackframe_error(class, method, frame.operand_stack.push(StackValue::Int(int << shift)))?;
+                }
                 Instruction::ArithmeticShiftIntRight() => {
                     let shift = wrap_stackframe_error(class, method, frame.operand_stack.pop_int(0))? as u8 & 0b00011111;
                     let int   = wrap_stackframe_error(class, method, frame.operand_stack.pop_int(0))?;
 
                     // rust does arithmetic shift on singed values
                     wrap_stackframe_error(class, method, frame.operand_stack.push(StackValue::Int(int >> shift)))?;
-                },
+                }
 
                 Instruction::ArrayLength() => {
                     let array_reference = wrap_stackframe_error(class, method, frame.operand_stack.pop_reference(0))?;
@@ -1554,7 +1561,14 @@ impl JVM {
                     let new_object = self.heap_area.make_object(&self.class_store, class_index);
 
                     wrap_stackframe_error(class, method, frame.operand_stack.push(StackValue::Reference(new_object)))?;
-                },
+                }
+
+                Instruction::OrInt() => {
+                    let value_0 = wrap_stackframe_error(class, method, frame.operand_stack.pop_int(0))?;
+                    let value_1 = wrap_stackframe_error(class, method, frame.operand_stack.pop_int(0))?;
+
+                    wrap_stackframe_error(class, method, frame.operand_stack.push(StackValue::Int(value_0 | value_1)))?;
+                }
 
                 Instruction::Pop() => {
                     wrap_stackframe_error(class, method, frame.operand_stack.pop_computational_1(0))?;