diff --git a/zokrates_core_test/tests/tests/arrays/fun_spread.zok b/zokrates_core_test/tests/tests/arrays/fun_spread.zok
index 861c05368..7a2ccd905 100644
--- a/zokrates_core_test/tests/tests/arrays/fun_spread.zok
+++ b/zokrates_core_test/tests/tests/arrays/fun_spread.zok
@@ -1,6 +1,6 @@
 import "utils/pack/bool/nonStrictUnpack256.zok" as unpack256;
 
 def main(field[2] inputs) -> bool[512] {
-    bool[512] preimage512 = [...unpack256(inputs[0], 254), ...unpack256(inputs[1], 254)];
+    bool[512] preimage512 = [...unpack256(inputs[0]), ...unpack256(inputs[1])];
     return preimage512;
 }
\ No newline at end of file
diff --git a/zokrates_stdlib/stdlib/ecc/babyjubjub.zok b/zokrates_stdlib/stdlib/ecc/babyjubjub.zok
index c7b97c3a6..85b469c0e 100644
--- a/zokrates_stdlib/stdlib/ecc/babyjubjub.zok
+++ b/zokrates_stdlib/stdlib/ecc/babyjubjub.zok
@@ -16,22 +16,21 @@ const field[2] G = [
     20819045374670962167435360035096875258406992893633759881276124905556507972311  // Gy
 ];
 
-const u32 bit_size = 254;
 
 def proofOfOwnership(field[2] pk, field sk) -> bool {
-    return edwardsProofOfOwnership(pk, sk, G, EDWARDS_A, EDWARDS_D, bit_size);
+    return edwardsProofOfOwnership(pk, sk, G, EDWARDS_A, EDWARDS_D);
 }
 
 def verifyEddsa(field[2] R, field S, field[2] A, u32[8] M0, u32[8] M1) -> bool {
-    return edwardsSignature(R, S, A, M0, M1, G, EDWARDS_A, EDWARDS_D, bit_size);
+    return edwardsSignature(R, S, A, M0, M1, G, EDWARDS_A, EDWARDS_D);
 }
 
 def compress(field[2] pt) -> bool[256] {
     field x = pt[0];
     field y = pt[1];
 
-    bool[256] xBits = unpack256(x, 254);
-    bool[256] mut yBits = unpack256(y, 254);
+    bool[256] xBits = unpack256(x);
+    bool[256] mut yBits = unpack256(y);
 
     bool sign = xBits[255];
     yBits[0] = sign;
diff --git a/zokrates_stdlib/stdlib/ecc/jubjub.zok b/zokrates_stdlib/stdlib/ecc/jubjub.zok
index 54f5e7687..96c82580c 100644
--- a/zokrates_stdlib/stdlib/ecc/jubjub.zok
+++ b/zokrates_stdlib/stdlib/ecc/jubjub.zok
@@ -15,12 +15,11 @@ const field[2] G = [
     44412834903739585386157632289020980010620626017712148233229312325549216099227  // Gy
 ];
 
-const u32 bit_size = 255;
 
 def proofOfOwnership(field[2] pk, field sk) -> bool {
-    return edwardsProofOfOwnership(pk, sk, G, EDWARDS_A, EDWARDS_D, bit_size);
+    return edwardsProofOfOwnership(pk, sk, G, EDWARDS_A, EDWARDS_D);
 }
 
 def verifyEddsa(field[2] R, field S, field[2] A, u32[8] M0, u32[8] M1) -> bool {
-    return edwardsSignature(R, S, A, M0, M1, G, EDWARDS_A, EDWARDS_D, bit_size);
+    return edwardsSignature(R, S, A, M0, M1, G, EDWARDS_A, EDWARDS_D);
 }
\ No newline at end of file
diff --git a/zokrates_stdlib/stdlib/ecc/proofOfOwnership.zok b/zokrates_stdlib/stdlib/ecc/proofOfOwnership.zok
index 54aa6b222..eb5844fa3 100644
--- a/zokrates_stdlib/stdlib/ecc/proofOfOwnership.zok
+++ b/zokrates_stdlib/stdlib/ecc/proofOfOwnership.zok
@@ -14,11 +14,10 @@ from "ecc/edwards" import scalarMul;
 ///    G: Generator point
 ///    EDWARDS_A: Coefficient `a` of the twisted Edwards curve
 ///    EDWARDS_D: Coefficient `d` of the twisted Edwards curve
-///    bit_size: Bit size of the twisted Edwards curve
 ///
 /// Returns true for pk/sk being a valid keypair, false otherwise.
-def main(field[2] pk, field sk, field[2] G, field EDWARDS_A, field EDWARDS_D, u32 bit_size) -> bool {
-    bool[256] sk_bits = unpack256(sk, bit_size);
+def main(field[2] pk, field sk, field[2] G, field EDWARDS_A, field EDWARDS_D) -> bool {
+    bool[256] sk_bits = unpack256(sk);
     field[2] res = scalarMul(sk_bits, G, EDWARDS_A, EDWARDS_D);
     return (res[0] == pk[0] && res[1] == pk[1]);
 }
\ No newline at end of file
diff --git a/zokrates_stdlib/stdlib/ecc/verifyEddsa.zok b/zokrates_stdlib/stdlib/ecc/verifyEddsa.zok
index 75e88b4ea..29c8cecde 100644
--- a/zokrates_stdlib/stdlib/ecc/verifyEddsa.zok
+++ b/zokrates_stdlib/stdlib/ecc/verifyEddsa.zok
@@ -1,9 +1,10 @@
 import "hashes/sha256/1024bitPadded" as sha256;
-import "utils/pack/bool/nonStrictUnpack256" as unpack256bool;
 import "utils/pack/u32/nonStrictUnpack256" as unpack256u;
+import "utils/pack/bool/nonStrictUnpack256" as unpack256bool;
 from "utils/casts" import cast;
 from "ecc/edwards" import add, scalarMul, onCurve, orderCheck;
 
+
 /// Verifies an EdDSA Signature.
 ///
 /// Checks the correctness of a given EdDSA Signature (R,S) for the provided
@@ -23,22 +24,21 @@ from "ecc/edwards" import add, scalarMul, onCurve, orderCheck;
 ///    M1: 256bit array. Trailing 256bits of the message used to create S.
 ///    EDWARDS_A: Coefficient `a` of the twisted Edwards curve
 ///    EDWARDS_D: Coefficient `d` of the twisted Edwards curve
-///    bit_size: Bit size of the twisted Edwards curve
 ///
 /// Returns:
 ///     Return true for S being a valid EdDSA Signature, false otherwise.
-def main(field[2] R, field S, field[2] A, u32[8] M0, u32[8] M1, field[2] G, field EDWARDS_A, field EDWARDS_D, u32 bit_size) -> bool {
+def main(field[2] R, field S, field[2] A, u32[8] M0, u32[8] M1, field[2] G, field EDWARDS_A, field EDWARDS_D) -> bool {
     // Check if R is on curve and if it is not in a small subgroup. A is public input and can be checked offline
     assert(onCurve(R, EDWARDS_A, EDWARDS_D)); // throws if R is not on curve
     assert(orderCheck(R, EDWARDS_A, EDWARDS_D));
 
-    u32[8] Rx = unpack256u(R[0], bit_size);
-    u32[8] Ax = unpack256u(A[0], bit_size);
+    u32[8] Rx = unpack256u(R[0]);
+    u32[8] Ax = unpack256u(A[0]);
 
     u32[8] h = sha256(Rx, Ax, M0, M1);
     bool[256] hRAM = cast(h);
 
-    bool[256] sBits = unpack256bool(S, bit_size);
+    bool[256] sBits = unpack256bool(S);
     field[2] lhs = scalarMul(sBits, G, EDWARDS_A, EDWARDS_D);
 
     field[2] AhRAM = scalarMul(hRAM, A, EDWARDS_A, EDWARDS_D);
diff --git a/zokrates_stdlib/stdlib/utils/pack/bool/nonStrictUnpack256.zok b/zokrates_stdlib/stdlib/utils/pack/bool/nonStrictUnpack256.zok
index 070a865a9..6106a202c 100644
--- a/zokrates_stdlib/stdlib/utils/pack/bool/nonStrictUnpack256.zok
+++ b/zokrates_stdlib/stdlib/utils/pack/bool/nonStrictUnpack256.zok
@@ -1,11 +1,14 @@
 import "./unpack_unchecked";
+from "field" import FIELD_SIZE_IN_BITS;
 
-// Unpack a field element as 256 big-endian bits
+// Unpack a field element as 256 big-endian bits.
+// Size of p differs among different fields. 
+// For example, for bn128 |p| is 254 bit , for bls12-381 |p| is 255.
 // Note: uniqueness of the output is not guaranteed
 // For example, `0` can map to `[0, 0, ..., 0]` or to `bits(p)`
-def main(field i, u32 bit_size) -> bool[256] {
-    assert(bit_size <= 256);
-    u32 padding_size = 256 - bit_size;
-    bool[bit_size] b = unpack_unchecked(i);
+def main(field i) -> bool[256] {
+    assert(FIELD_SIZE_IN_BITS <= 256);
+    u32 padding_size = 256 - FIELD_SIZE_IN_BITS;
+    bool[FIELD_SIZE_IN_BITS] b = unpack_unchecked(i);
     return [...[false; padding_size], ...b];
 }
\ No newline at end of file
diff --git a/zokrates_stdlib/stdlib/utils/pack/u32/nonStrictUnpack256.zok b/zokrates_stdlib/stdlib/utils/pack/u32/nonStrictUnpack256.zok
index 3a3a70039..1661a1a51 100644
--- a/zokrates_stdlib/stdlib/utils/pack/u32/nonStrictUnpack256.zok
+++ b/zokrates_stdlib/stdlib/utils/pack/u32/nonStrictUnpack256.zok
@@ -4,6 +4,6 @@ import "../../casts/bool_256_to_u32_8" as from_bits;
 // Unpack a field element as a u32[8] (big-endian)
 // Note: uniqueness of the output is not guaranteed
 // For example, `0` can map to `[0, 0, ..., 0]` or to `bits(p)`
-def main(field i, u32 bit_size) -> u32[8] {
-    return from_bits(unpack(i, bit_size));
+def main(field i) -> u32[8] {
+    return from_bits(unpack(i));
 }
\ No newline at end of file
diff --git a/zokrates_stdlib/tests/tests/ecc/jubjub/verifyEddsa.zok b/zokrates_stdlib/tests/tests/ecc/jubjub/verifyEddsa.zok
index ce07cdc51..8875071fc 100644
--- a/zokrates_stdlib/tests/tests/ecc/jubjub/verifyEddsa.zok
+++ b/zokrates_stdlib/tests/tests/ecc/jubjub/verifyEddsa.zok
@@ -5,8 +5,6 @@ from "ecc/jubjub" import verifyEddsa;
 // https://github.com/Zokrates/pycrypto
 def main() {
 
-    // TODO: Jubjub currently work only for keys <=254 bit long
-    // With the following keys should also work:
     field[2] R = [32866767109220564315580607107081162920517672350707254238793964527466586251974, 31852087390335520207922973662676180854641055992940928475111512263314053365736];
     field S = 43627586196239283173178511316555190744314536456808505435494185841008559853678;
     
diff --git a/zokrates_stdlib/tests/tests/utils/pack/bool/nonStrictUnpack256.json b/zokrates_stdlib/tests/tests/utils/pack/bool/nonStrictUnpack256.json
index e7c734581..2114786b4 100644
--- a/zokrates_stdlib/tests/tests/utils/pack/bool/nonStrictUnpack256.json
+++ b/zokrates_stdlib/tests/tests/utils/pack/bool/nonStrictUnpack256.json
@@ -1,10 +1,11 @@
+
 {
   "entry_point": "./tests/tests/utils/pack/bool/nonStrictUnpack256.zok",
-  "curves": ["Bls12_381"],
+  "curves": ["Bn128"],
   "tests": [
     {
       "input": {
-        "values": []
+        "values": [[false, false, true, true, false, false, false, false, false, true, true, false, false, true, false, false, false, true, false, false, true, true, true, false, false, true, true, true, false, false, true, false, true, true, true, false, false, false, false, true, false, false, true, true, false, false, false, true, true, false, true, false, false, false, false, false, false, false, true, false, true, false, false, true, true, false, true, true, true, false, false, false, false, true, false, true, false, false, false, false, false, true, false, false, false, true, false, true, true, false, true, true, false, true, true, false, true, false, false, false, false, false, false, true, true, false, false, false, false, false, false, true, false, true, false, true, true, false, false, false, false, true, false, true, true, true, false, true, false, false, true, false, true, false, false, false, false, false, true, true, false, false, true, true, true, true, true, false, true, false, false, false, false, true, false, false, true, false, false, false, false, true, true, true, true, false, false, true, true, false, true, true, true, false, false, true, false, true, true, true, false, false, false, false, true, false, false, true, false, false, false, true, false, true, false, false, false, false, true, true, true, true, true, false, false, false, false, true, true, true, true, true, false, true, false, true, true, false, false, true, false, false, true, true, true, true, true, true, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false]]
       },
       "output": {
         "Ok": {
@@ -13,4 +14,4 @@
       }
     }
   ]
-}
+}
\ No newline at end of file
diff --git a/zokrates_stdlib/tests/tests/utils/pack/bool/nonStrictUnpack256.zok b/zokrates_stdlib/tests/tests/utils/pack/bool/nonStrictUnpack256.zok
index 8e8746b26..b600f9990 100644
--- a/zokrates_stdlib/tests/tests/utils/pack/bool/nonStrictUnpack256.zok
+++ b/zokrates_stdlib/tests/tests/utils/pack/bool/nonStrictUnpack256.zok
@@ -1,50 +1,34 @@
 import "utils/pack/bool/nonStrictUnpack256" as unpack256;
+from "field" import FIELD_MIN, FIELD_MAX;
 
-def testFive() -> bool {
-    bool[256] b = unpack256(5, 254);
-    assert(b == [false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, true, false, true]);
-    
-    bool[256] b = unpack256(5, 255);
-    assert(b == [false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, true, false, true]);
-    
+def testZero() -> bool {
+    bool[256] zero_bool = [false; 256];
+    assert(unpack256(FIELD_MIN) == zero_bool);
+    assert(unpack256(FIELD_MAX + 1) == zero_bool);
     return true;
 }
 
-def testZero() -> bool {
-    bool[256] b = unpack256(0, 254);
-    assert(b == [false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false]);
-
-    bool[256] b = unpack256(0, 255);
-    assert(b == [false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false]);
-
+def testFive() -> bool {
+    bool[256] five_bool = [...[false; 253], ...[true, false, true]];
+    assert(unpack256(FIELD_MIN + 5) == five_bool);
+    assert(unpack256(FIELD_MAX + 1 + 5) == five_bool);
     return true;
 }
 
 def testLarge() -> bool {
-    bool[256] b = unpack256(14474011154664524427946373126085988481658748083205070504932198000989141204991, 254);
+    bool[256] b = unpack256(14474011154664524427946373126085988481658748083205070504932198000989141204991);
     assert(b == [false, false, false, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true]);
-    
-    bool[256] b = unpack256(28948022309329048855892746252171976963317496166410141009864396001978282409983, 255);
-    assert(b == [false, false, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true]);
-    
     return true;
 }
 
-def testMax() -> bool {
-    // bn128 
-    bool[256] b = unpack256(21888242871839275222246405745257275088548364400416034343698204186575808495616, 254);
-    assert(b == [false, false, true, true, false, false, false, false, false, true, true, false, false, true, false, false, false, true, false, false, true, true, true, false, false, true, true, true, false, false, true, false, true, true, true, false, false, false, false, true, false, false, true, true, false, false, false, true, true, false, true, false, false, false, false, false, false, false, true, false, true, false, false, true, true, false, true, true, true, false, false, false, false, true, false, true, false, false, false, false, false, true, false, false, false, true, false, true, true, false, true, true, false, true, true, false, true, false, false, false, false, false, false, true, true, false, false, false, false, false, false, true, false, true, false, true, true, false, false, false, false, true, false, true, true, true, false, true, false, false, true, false, true, false, false, false, false, false, true, true, false, false, true, true, true, true, true, false, true, false, false, false, false, true, false, false, true, false, false, false, false, true, true, true, true, false, false, true, true, false, true, true, true, false, false, true, false, true, true, true, false, false, false, false, true, false, false, true, false, false, false, true, false, true, false, false, false, false, true, true, true, true, true, false, false, false, false, true, true, true, true, true, false, true, false, true, true, false, false, true, false, false, true, true, true, true, true, true, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false]);
-    
-    // bls12_381
-    bool[256] b = unpack256(52435875175126190479447740508185965837690552500527637822603658699938581184512, 255);
-    assert(b == [false, true, true, true, false, false, true, true, true, true, true, false, true, true, false, true, true, false, true, false, false, true, true, true, false, true, false, true, false, false, true, true, false, false, true, false, true, false, false, true, true, false, false, true, true, true, false, true, false, true, true, true, true, true, false, true, false, true, false, false, true, false, false, false, false, false, true, true, false, false, true, true, false, false, true, true, true, false, false, true, true, true, false, true, true, false, false, false, false, false, false, false, true, false, false, false, false, false, false, false, true, false, false, true, true, false, true, false, false, false, false, true, true, true, false, true, true, false, false, false, false, false, false, false, false, true, false, true, false, true, false, true, false, false, true, true, true, false, true, true, true, true, false, true, true, false, true, false, false, true, false, false, false, false, false, false, false, false, true, false, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, false, false, true, false, true, true, false, true, true, true, true, true, true, true, true, true, false, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false]);
-    
+def testMax(bool[256] max_bool) -> bool {
+    assert(unpack256(FIELD_MAX) == max_bool);
     return true;
 }
 
- def main() {
+ def main(public bool[256] max_bool) {
     assert(testFive());
-    assert(testMax());
+    assert(testMax(max_bool));
     assert(testZero());
     assert(testLarge());
     return;
diff --git a/zokrates_stdlib/tests/tests/utils/pack/bool/nonStrictUnpack256_bls12_381.json b/zokrates_stdlib/tests/tests/utils/pack/bool/nonStrictUnpack256_bls12_381.json
new file mode 100644
index 000000000..9059e234d
--- /dev/null
+++ b/zokrates_stdlib/tests/tests/utils/pack/bool/nonStrictUnpack256_bls12_381.json
@@ -0,0 +1,16 @@
+{
+  "entry_point": "./tests/tests/utils/pack/bool/nonStrictUnpack256.zok",
+  "curves": ["Bls12_381"],
+  "tests": [
+    {
+      "input": {
+        "values": [[false, true, true, true, false, false, true, true, true, true, true, false, true, true, false, true, true, false, true, false, false, true, true, true, false, true, false, true, false, false, true, true, false, false, true, false, true, false, false, true, true, false, false, true, true, true, false, true, false, true, true, true, true, true, false, true, false, true, false, false, true, false, false, false, false, false, true, true, false, false, true, true, false, false, true, true, true, false, false, true, true, true, false, true, true, false, false, false, false, false, false, false, true, false, false, false, false, false, false, false, true, false, false, true, true, false, true, false, false, false, false, true, true, true, false, true, true, false, false, false, false, false, false, false, false, true, false, true, false, true, false, true, false, false, true, true, true, false, true, true, true, true, false, true, true, false, true, false, false, true, false, false, false, false, false, false, false, false, true, false, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, false, false, true, false, true, true, false, true, true, true, true, true, true, true, true, true, false, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false]]
+      },
+      "output": {
+        "Ok": {
+          "value": []
+        }
+      }
+    }
+  ]
+}
diff --git a/zokrates_stdlib/tests/tests/utils/pack/u32/nonStrictUnpack256.json b/zokrates_stdlib/tests/tests/utils/pack/u32/nonStrictUnpack256.json
index 5a8dc41e3..00815fc75 100644
--- a/zokrates_stdlib/tests/tests/utils/pack/u32/nonStrictUnpack256.json
+++ b/zokrates_stdlib/tests/tests/utils/pack/u32/nonStrictUnpack256.json
@@ -1,6 +1,6 @@
 {
   "entry_point": "./tests/tests/utils/pack/u32/nonStrictUnpack256.zok",
-  "curves": ["Bls12_381"],
+  "curves": ["Bn128"],
   "tests": [
     {
       "input": {
diff --git a/zokrates_stdlib/tests/tests/utils/pack/u32/nonStrictUnpack256.zok b/zokrates_stdlib/tests/tests/utils/pack/u32/nonStrictUnpack256.zok
index 67be9afda..4a865fb6e 100644
--- a/zokrates_stdlib/tests/tests/utils/pack/u32/nonStrictUnpack256.zok
+++ b/zokrates_stdlib/tests/tests/utils/pack/u32/nonStrictUnpack256.zok
@@ -1,41 +1,26 @@
 import "utils/pack/u32/nonStrictUnpack256" as unpack256;
 
 def testFive() -> bool {
-    u32[8] b = unpack256(5, 254);
+    u32[8] b = unpack256(5);
     assert(b == [0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000005]);
-
-    u32[8] b = unpack256(5, 255);
-    assert(b == [0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000005]);
-
     return true;
 }
 
 def testZero() -> bool {
-    u32[8] b = unpack256(0, 254);
-    assert(b == [0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000]);
-    
-    u32[8] b = unpack256(0, 255);
+    u32[8] b = unpack256(0);
     assert(b == [0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000]);
     return true;
 }
 
 def testLarge() -> bool {
-    u32[8] b = unpack256(14474011154664524427946373126085988481658748083205070504932198000989141204991, 254);
+    u32[8] b = unpack256(14474011154664524427946373126085988481658748083205070504932198000989141204991);
     assert(b == [0x1fffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff]);
-
-    u32[8] b = unpack256(28948022309329048855892746252171976963317496166410141009864396001978282409983, 255);
-    assert(b == [0x3fffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff]);
     return true;
 }
 
 def testMax() -> bool {
-    // bn128 
-    u32[8] b = unpack256(21888242871839275222246405745257275088548364400416034343698204186575808495616, 254);
+    u32[8] b = unpack256(21888242871839275222246405745257275088548364400416034343698204186575808495616);
     assert(b == [0x30644e72, 0xe131a029, 0xb85045b6, 0x8181585d, 0x2833e848, 0x79b97091, 0x43e1f593, 0xf0000000]);
-
-    // bls12_381
-    u32[8] b = unpack256(52435875175126190479447740508185965837690552500527637822603658699938581184512, 255);
-    assert(b == [0x73eda753, 0x299d7d48, 0x3339d808, 0x09a1d805, 0x53bda402, 0xfffe5bfe, 0xffffffff, 0x00000000]);
     return true;
 }
 
diff --git a/zokrates_test/tests/out_of_range.rs b/zokrates_test/tests/out_of_range.rs
index 730485ae7..ea2800252 100644
--- a/zokrates_test/tests/out_of_range.rs
+++ b/zokrates_test/tests/out_of_range.rs
@@ -133,7 +133,7 @@ fn unpack256_unchecked() {
         import "utils/pack/bool/nonStrictUnpack256";
 
 		def main(private field a) {
-	        bool[256] bits = nonStrictUnpack256(a, 254);
+	        bool[256] bits = nonStrictUnpack256(a);
 			assert(bits[255]);
             return;
         }