diff --git a/src/engine.cairo b/src/engine.cairo
index 6a65f378..afefbb2f 100644
--- a/src/engine.cairo
+++ b/src/engine.cairo
@@ -50,10 +50,14 @@ pub trait EngineTrait {
     fn has_flag(ref self: Engine, flag: ScriptFlags) -> bool;
     // Return the script since last OP_CODESEPARATOR
     fn sub_script(ref self: Engine) -> ByteArray;
+    // Ensure the stack size is within limits
+    fn check_stack_size(ref self: Engine) -> Result<(), felt252>;
     // Print engine data as a JSON object
     fn json(ref self: Engine);
 }
 
+pub const MAX_STACK_SIZE: u32 = 1000;
+
 pub impl EngineImpl of EngineTrait {
     fn new(
         script_pubkey: @ByteArray, transaction: Transaction, tx_idx: u32, flags: u32, amount: i64
@@ -135,8 +139,8 @@ pub impl EngineImpl of EngineTrait {
         if res.is_err() {
             return Result::Err(res.unwrap_err());
         }
+        self.check_stack_size()?;
         self.opcode_idx += 1;
-
         if self.opcode_idx >= script.len() {
             if self.cond_stack.len() > 0 {
                 return Result::Err(Error::SCRIPT_UNBALANCED_CONDITIONAL_STACK);
@@ -183,6 +187,11 @@ pub impl EngineImpl of EngineTrait {
                     err = res.unwrap_err();
                     break;
                 }
+                let res = self.check_stack_size();
+                if res.is_err() {
+                    err = res.unwrap_err();
+                    break;
+                }
                 self.opcode_idx += 1;
             };
             if err != '' {
@@ -245,6 +254,13 @@ pub impl EngineImpl of EngineTrait {
         return sub_script;
     }
 
+    fn check_stack_size(ref self: Engine) -> Result<(), felt252> {
+        if self.dstack.len() + self.astack.len() > MAX_STACK_SIZE {
+            return Result::Err(Error::SCRIPT_STACK_SIZE_EXCEEDED);
+        }
+        return Result::Ok(());
+    }
+
     fn json(ref self: Engine) {
         self.dstack.json();
     }
diff --git a/src/errors.cairo b/src/errors.cairo
index d2b21ad9..3722f58d 100644
--- a/src/errors.cairo
+++ b/src/errors.cairo
@@ -14,6 +14,7 @@ pub mod Error {
     pub const FINALIZED_TX_CLTV: felt252 = 'Finalized tx in OP_CLTV';
     pub const INVALID_TX_VERSION: felt252 = 'Invalid transaction version';
     pub const SCRIPT_INVALID: felt252 = 'Invalid script data';
+    pub const SCRIPT_STACK_SIZE_EXCEEDED: felt252 = 'Script stack size exceeded';
 }
 
 pub fn byte_array_err(err: felt252) -> ByteArray {