diff --git a/crates/uplc/src/machine.rs b/crates/uplc/src/machine.rs
index 6efbdf3e..1e54f9e6 100644
--- a/crates/uplc/src/machine.rs
+++ b/crates/uplc/src/machine.rs
@@ -320,7 +320,7 @@ impl Machine {
     }
 
     fn eval_builtin_app(&mut self, runtime: BuiltinRuntime) -> Result<Value, Error> {
-        let cost = runtime.to_ex_budget(&self.costs.builtin_costs);
+        let cost = runtime.to_ex_budget(&self.costs.builtin_costs)?;
 
         self.spend_budget(cost)?;
 
diff --git a/crates/uplc/src/machine/cost_model.rs b/crates/uplc/src/machine/cost_model.rs
index e2a1503a..9eb8124d 100644
--- a/crates/uplc/src/machine/cost_model.rs
+++ b/crates/uplc/src/machine/cost_model.rs
@@ -1,5 +1,6 @@
-use super::Value;
+use super::{runtime, Error, Value};
 use crate::builtins::DefaultFunction;
+use num_bigint::BigInt;
 use pallas_primitives::conway::Language;
 use std::collections::HashMap;
 
@@ -1741,8 +1742,8 @@ impl Default for BuiltinCosts {
 }
 
 impl BuiltinCosts {
-    pub fn to_ex_budget(&self, fun: DefaultFunction, args: &[Value]) -> ExBudget {
-        match fun {
+    pub fn to_ex_budget(&self, fun: DefaultFunction, args: &[Value]) -> Result<ExBudget, Error> {
+        Ok(match fun {
             DefaultFunction::AddInteger => ExBudget {
                 mem: self
                     .add_integer
@@ -2307,18 +2308,31 @@ impl BuiltinCosts {
                     .cpu
                     .cost(args[0].to_ex_mem(), args[1].to_ex_mem()),
             },
-            DefaultFunction::IntegerToByteString => ExBudget {
-                mem: self.integer_to_byte_string.mem.cost(
-                    args[0].to_ex_mem(),
-                    args[1].to_ex_mem(),
-                    args[2].to_ex_mem(),
-                ),
-                cpu: self.integer_to_byte_string.cpu.cost(
-                    args[0].to_ex_mem(),
-                    args[1].to_ex_mem(),
-                    args[2].to_ex_mem(),
-                ),
-            },
+            DefaultFunction::IntegerToByteString => {
+                let uplc_int = args[1].unwrap_integer()?;
+
+                if uplc_int > &BigInt::from(runtime::INTEGER_TO_BYTE_STRING_MAXIMUM_OUTPUT_LENGTH) {
+                    return Err(Error::IntegerToByteStringSizeTooBig(
+                        uplc_int.clone(),
+                        runtime::INTEGER_TO_BYTE_STRING_MAXIMUM_OUTPUT_LENGTH,
+                    ));
+                }
+
+                let arg1 = u64::try_from(uplc_int).unwrap().try_into().unwrap();
+
+                ExBudget {
+                    mem: self.integer_to_byte_string.mem.cost(
+                        args[0].to_ex_mem(),
+                        arg1,
+                        args[2].to_ex_mem(),
+                    ),
+                    cpu: self.integer_to_byte_string.cpu.cost(
+                        args[0].to_ex_mem(),
+                        arg1,
+                        args[2].to_ex_mem(),
+                    ),
+                }
+            }
             DefaultFunction::ByteStringToInteger => ExBudget {
                 mem: self
                     .byte_string_to_integer
@@ -2329,7 +2343,7 @@ impl BuiltinCosts {
                     .cpu
                     .cost(args[0].to_ex_mem(), args[1].to_ex_mem()),
             },
-        }
+        })
     }
 }
 
diff --git a/crates/uplc/src/machine/runtime.rs b/crates/uplc/src/machine/runtime.rs
index c69bd038..25387f12 100644
--- a/crates/uplc/src/machine/runtime.rs
+++ b/crates/uplc/src/machine/runtime.rs
@@ -31,7 +31,7 @@ const BLST_P1_COMPRESSED_SIZE: usize = 48;
 
 const BLST_P2_COMPRESSED_SIZE: usize = 96;
 
-const INTEGER_TO_BYTE_STRING_MAXIMUM_OUTPUT_LENGTH: i64 = 8192;
+pub const INTEGER_TO_BYTE_STRING_MAXIMUM_OUTPUT_LENGTH: i64 = 8192;
 
 //#[derive(std::cmp::PartialEq)]
 //pub enum EvalMode {
@@ -96,7 +96,7 @@ impl BuiltinRuntime {
         Ok(())
     }
 
-    pub fn to_ex_budget(&self, costs: &BuiltinCosts) -> ExBudget {
+    pub fn to_ex_budget(&self, costs: &BuiltinCosts) -> Result<ExBudget, Error> {
         costs.to_ex_budget(self.fun, &self.args)
     }
 }
@@ -1388,12 +1388,13 @@ impl DefaultFunction {
                     return Err(Error::IntegerToByteStringNegativeSize(size.clone()));
                 }
 
-                if size > &INTEGER_TO_BYTE_STRING_MAXIMUM_OUTPUT_LENGTH.into() {
-                    return Err(Error::IntegerToByteStringSizeTooBig(
-                        size.clone(),
-                        INTEGER_TO_BYTE_STRING_MAXIMUM_OUTPUT_LENGTH,
-                    ));
-                }
+                // Since this is checked at cost time it is no longer needed
+                // if size > &INTEGER_TO_BYTE_STRING_MAXIMUM_OUTPUT_LENGTH.into() {
+                //     return Err(Error::IntegerToByteStringSizeTooBig(
+                //         size.clone(),
+                //         INTEGER_TO_BYTE_STRING_MAXIMUM_OUTPUT_LENGTH,
+                //     ));
+                // }
 
                 if size.is_zero()
                     && integer_log2(input.clone())