diff --git a/src/vstc/virtual_machine/bytecode_decoder.rs b/src/vstc/virtual_machine/bytecode_decoder.rs
index 8bc4999..1f7f9d8 100644
--- a/src/vstc/virtual_machine/bytecode_decoder.rs
+++ b/src/vstc/virtual_machine/bytecode_decoder.rs
@@ -17,6 +17,7 @@ pub struct BytecodeDecoder {
 #[derive(PartialEq)]
 pub enum BytecodeType {
   End = 0x00,
+  Void = 0x01,
   Undefined = 0x02,
   Null = 0x03,
   False = 0x04,
@@ -37,6 +38,7 @@ impl BytecodeType {
 
     return match byte {
       0x00 => End,
+      0x01 => Void,
       0x02 => Undefined,
       0x03 => Null,
       0x04 => False,
@@ -77,6 +79,7 @@ impl BytecodeDecoder {
   pub fn decode_val(&mut self, registers: &Vec<Val>) -> Val {
     return match self.decode_type() {
       BytecodeType::End => std::panic!("Cannot decode end"),
+      BytecodeType::Void => Val::Void,
       BytecodeType::Undefined => Val::Undefined,
       BytecodeType::Null => Val::Null,
       BytecodeType::False => Val::Bool(false),
diff --git a/src/vstc/virtual_machine/operations.rs b/src/vstc/virtual_machine/operations.rs
index d964fb0..222bb78 100644
--- a/src/vstc/virtual_machine/operations.rs
+++ b/src/vstc/virtual_machine/operations.rs
@@ -260,7 +260,12 @@ pub fn op_sub(left: Val, right: Val) -> Val {
         return Val::Undefined;
       }
 
-      return array_data[right_index].clone();
+      let res = array_data[right_index].clone();
+
+      return match res {
+        Val::Void => Val::Undefined,
+        _ => res,
+      };
     },
     Val::Object(object_data) => {
       return object_data
diff --git a/src/vstc/virtual_machine/vs_pointer.rs b/src/vstc/virtual_machine/vs_pointer.rs
index 68de7c9..1e6606c 100644
--- a/src/vstc/virtual_machine/vs_pointer.rs
+++ b/src/vstc/virtual_machine/vs_pointer.rs
@@ -34,6 +34,7 @@ impl ValTrait for VsPointer {
 
     return match bd.decode_type() {
       BytecodeType::End => std::panic!("Invalid: pointer to end"),
+      BytecodeType::Void => std::panic!("Invalid: pointer to void"),
       BytecodeType::Undefined => VsType::Undefined,
       BytecodeType::Null => VsType::Null,
       BytecodeType::False => VsType::Bool,