diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7ea37436f4..30d5ea647a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,14 @@
 
 #### Upcoming Changes
 
+* Implement hints on uint384 lib (Part 2) [#971](https://github.com/lambdaclass/cairo-rs/pull/971)
+
+    `BuiltinHintProcessor` now supports the following hint:
+
+    ```python
+        memory[ap] = 1 if 0 <= (ids.a.d2 % PRIME) < 2 ** 127 else 0
+    ```
+
  * Add alternative hint code for hint on _block_permutation used by 0.10.3 whitelist [#958](https://github.com/lambdaclass/cairo-rs/pull/958)
 
      `BuiltinHintProcessor` now supports the following hint:
diff --git a/cairo_programs/uint384.cairo b/cairo_programs/uint384.cairo
index ecb135dae8..f578b29eb3 100644
--- a/cairo_programs/uint384.cairo
+++ b/cairo_programs/uint384.cairo
@@ -97,6 +97,22 @@ namespace uint384_lib {
         return (res,);
     }
 
+    // Returns 1 if the signed integer is nonnegative.
+    @known_ap_change
+    func signed_nn{range_check_ptr}(a: Uint384) -> (res: felt) {
+        %{ memory[ap] = 1 if 0 <= (ids.a.d2 % PRIME) < 2 ** 127 else 0 %}
+        jmp non_negative if [ap] != 0, ap++;
+
+        assert [range_check_ptr] = a.d2 - 2 ** 127;
+        let range_check_ptr = range_check_ptr + 1;
+        return (res=0);
+
+        non_negative:
+        assert [range_check_ptr] = a.d2 + 2 ** 127;
+        let range_check_ptr = range_check_ptr + 1;
+        return (res=1);
+    }
+
     // Adds two integers. Returns the result as a 384-bit integer and the (1-bit) carry.
     // Doesn't verify that the result is a proper Uint384, that's now the responsibility of the calling function
     func _add_no_uint384_check{range_check_ptr}(a: Uint384, b: Uint384) -> (
@@ -523,6 +539,14 @@ func test_uint384_operations{range_check_ptr}() {
     assert root.d1 = 916102188;
     assert root.d2 = 0;
 
+    let g = Uint384(1, 1, 1);
+    let (sign_g) = uint384_lib.signed_nn(g);
+    assert sign_g = 1;
+
+    let h = Uint384(0, 0, 170141183460469231731687303715884105729);
+    let (sign_h) = uint384_lib.signed_nn(h);
+    assert sign_h = 0;
+
     return ();
 }
 
diff --git a/src/hint_processor/builtin_hint_processor/builtin_hint_processor_definition.rs b/src/hint_processor/builtin_hint_processor/builtin_hint_processor_definition.rs
index 60ed30726f..8ae2f7f60e 100644
--- a/src/hint_processor/builtin_hint_processor/builtin_hint_processor_definition.rs
+++ b/src/hint_processor/builtin_hint_processor/builtin_hint_processor_definition.rs
@@ -73,8 +73,8 @@ use crate::hint_processor::builtin_hint_processor::skip_next_instruction::skip_n
 
 use super::ec_utils::{chained_ec_op_random_ec_point_hint, random_ec_point_hint, recover_y_hint};
 use super::uint384::{
-    add_no_uint384_check, uint384_split_128, uint384_sqrt, uint384_unsigned_div_rem,
-    uint384_unsigned_div_rem_expanded,
+    add_no_uint384_check, uint384_signed_nn, uint384_split_128, uint384_sqrt,
+    uint384_unsigned_div_rem, uint384_unsigned_div_rem_expanded,
 };
 
 pub struct HintProcessorData {
@@ -472,6 +472,9 @@ impl HintProcessor for BuiltinHintProcessor {
             hint_code::UINT384_SQRT => {
                 uint384_sqrt(vm, &hint_data.ids_data, &hint_data.ap_tracking)
             }
+            hint_code::UINT384_SIGNED_NN => {
+                uint384_signed_nn(vm, &hint_data.ids_data, &hint_data.ap_tracking)
+            }
             hint_code::UINT256_MUL_DIV_MOD => {
                 uint256_mul_div_mod(vm, &hint_data.ids_data, &hint_data.ap_tracking)
             }
diff --git a/src/hint_processor/builtin_hint_processor/hint_code.rs b/src/hint_processor/builtin_hint_processor/hint_code.rs
index 37151f829f..9d882207a0 100644
--- a/src/hint_processor/builtin_hint_processor/hint_code.rs
+++ b/src/hint_processor/builtin_hint_processor/hint_code.rs
@@ -727,6 +727,8 @@ root_split = split(root, num_bits_shift=128, length=3)
 ids.root.d0 = root_split[0]
 ids.root.d1 = root_split[1]
 ids.root.d2 = root_split[2]";
+pub(crate) const UINT384_SIGNED_NN: &str =
+    "memory[ap] = 1 if 0 <= (ids.a.d2 % PRIME) < 2 ** 127 else 0";
 
 #[cfg(feature = "skip_next_instruction_hint")]
 pub(crate) const SKIP_NEXT_INSTRUCTION: &str = "skip_next_instruction()";
diff --git a/src/hint_processor/builtin_hint_processor/uint384.rs b/src/hint_processor/builtin_hint_processor/uint384.rs
index 055d907dd7..3781c0bb85 100644
--- a/src/hint_processor/builtin_hint_processor/uint384.rs
+++ b/src/hint_processor/builtin_hint_processor/uint384.rs
@@ -15,6 +15,7 @@ use crate::{
 
 use super::hint_utils::{
     get_integer_from_var_name, get_relocatable_from_var_name, insert_value_from_var_name,
+    insert_value_into_ap,
 };
 use super::secp::bigint_utils::BigInt3;
 // Notes: Hints in this lib use the type Uint384, which is equal to common lib's BigInt3
@@ -302,6 +303,23 @@ pub fn uint384_sqrt(
     }
     Ok(())
 }
+
+/* Implements Hint:
+   memory[ap] = 1 if 0 <= (ids.a.d2 % PRIME) < 2 ** 127 else 0
+*/
+pub fn uint384_signed_nn(
+    vm: &mut VirtualMachine,
+    ids_data: &HashMap<String, HintReference>,
+    ap_tracking: &ApTracking,
+) -> Result<(), HintError> {
+    let a_addr = get_relocatable_from_var_name("a", vm, ids_data, ap_tracking)?;
+    let a_d2 = vm
+        .get_integer((a_addr + 2)?)
+        .map_err(|_| HintError::IdentifierHasNoMember("a".to_string(), "d2".to_string()))?;
+    let res = Felt252::from((a_d2.bits() <= 127) as u32);
+    insert_value_into_ap(vm, res)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -705,4 +723,71 @@ mod tests {
             Err(HintError::AssertionFailed(s)) if s == "assert 0 <= root < 2 ** 192"
         );
     }
+
+    #[test]
+    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+    fn run_signed_nn_ok_positive() {
+        let mut vm = vm_with_range_check!();
+        //Initialize fp
+        vm.run_context.fp = 3;
+        //Create hint_data
+        let ids_data = non_continuous_ids_data![("a", -2)];
+        //Insert ids into memory
+        vm.segments = segments![
+            //a.d2
+            ((1, 3), 1)
+        ];
+        //Execute the hint
+        assert!(run_hint!(vm, ids_data, hint_code::UINT384_SIGNED_NN).is_ok());
+        //Check hint memory inserts
+        check_memory![
+            vm.segments.memory,
+            // ap
+            ((1, 0), 1)
+        ];
+    }
+
+    #[test]
+    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+    fn run_signed_nn_missing_identifier() {
+        let mut vm = vm_with_range_check!();
+        //Initialize fp
+        vm.run_context.fp = 3;
+        //Create hint_data
+        let ids_data = non_continuous_ids_data![("a", -2)];
+        //Insert ids into memory
+        vm.segments = segments![
+            //a.d0
+            ((1, 1), 1),
+            //a.d1
+            ((1, 2), 1) //a.d2
+        ];
+        //Execute the hint
+        assert_matches!(run_hint!(vm, ids_data, hint_code::UINT384_SIGNED_NN),
+            Err(HintError::IdentifierHasNoMember(s1, s2)) if s1 == "a" && s2 == "d2"
+        );
+    }
+
+    #[test]
+    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+    fn run_signed_nn_ok_negative() {
+        let mut vm = vm_with_range_check!();
+        //Initialize fp
+        vm.run_context.fp = 3;
+        //Create hint_data
+        let ids_data = non_continuous_ids_data![("a", -2)];
+        //Insert ids into memory
+        vm.segments = segments![
+            //a.d0
+            ((1, 3), 170141183460469231731687303715884105729_u128)
+        ];
+        //Execute the hint
+        assert!(run_hint!(vm, ids_data, hint_code::UINT384_SIGNED_NN).is_ok());
+        //Check hint memory inserts
+        check_memory![
+            vm.segments.memory,
+            // ap
+            ((1, 0), 0)
+        ];
+    }
 }