diff --git a/stint/io.nim b/stint/io.nim
index bc0d6d8..f792959 100644
--- a/stint/io.nim
+++ b/stint/io.nim
@@ -17,7 +17,7 @@ template static_check_size(T: typedesc[SomeInteger], bits: static[int]) =
   # To avoid a costly runtime check, we refuse storing into StUint types smaller
   # than the input type.
 
-  static: assert sizeof(T) * 8 <= bits, "Input type (" & $T &
+  static: doAssert sizeof(T) * 8 <= bits, "Input type (" & $T &
             ") cannot be stored in a multi-precision " &
             $bits & "-bit integer." &
             "\nUse a smaller input type instead. This is a compile-time check" &
@@ -32,7 +32,7 @@ func assignLo(result: var (UintImpl | IntImpl), n: SomeInteger) {.inline.} =
 func stuint*[T: SomeInteger](n: T, bits: static[int]): StUint[bits] {.inline.}=
   ## Converts an integer to an arbitrary precision integer.
 
-  assert n >= 0.T
+  doAssert n >= 0.T
   when result.data is UintImpl:
     static_check_size(T, bits)
     assignLo(result.data, n)
@@ -87,16 +87,16 @@ func skipPrefixes(current_idx: var int, str: string, radix: range[2..16]) {.inli
   if str.len < 2:
     return
 
-  assert current_idx == 0, "skipPrefixes only works for prefixes (position 0 and 1 of the string)"
+  doAssert current_idx == 0, "skipPrefixes only works for prefixes (position 0 and 1 of the string)"
   if str[0] == '0':
     if str[1] in {'x', 'X'}:
-      assert radix == 16, "Parsing mismatch, 0x prefix is only valid for a hexadecimal number (base 16)"
+      doAssert radix == 16, "Parsing mismatch, 0x prefix is only valid for a hexadecimal number (base 16)"
       current_idx = 2
     elif str[1] in {'o', 'O'}:
-      assert radix == 8, "Parsing mismatch, 0o prefix is only valid for an octal number (base 8)"
+      doAssert radix == 8, "Parsing mismatch, 0o prefix is only valid for an octal number (base 8)"
       current_idx = 2
     elif str[1] in {'b', 'B'}:
-      assert radix == 2, "Parsing mismatch, 0b prefix is only valid for a binary number (base 2)"
+      doAssert radix == 2, "Parsing mismatch, 0b prefix is only valid for a binary number (base 2)"
       current_idx = 2
 
 func nextNonBlank(current_idx: var int, s: string) {.inline.} =
@@ -116,7 +116,7 @@ func readDecChar(c: range['0'..'9']): int {.inline.}=
 func parse*[bits: static[int]](input: string, T: typedesc[Stuint[bits]], radix: static[uint8] = 10): T =
   ## Parse a string and store the result in a Stint[bits] or Stuint[bits].
 
-  static: assert (radix >= 2) and radix <= 16, "Only base from 2..16 are supported"
+  static: doAssert (radix >= 2) and radix <= 16, "Only base from 2..16 are supported"
   # TODO: use static[range[2 .. 16]], not supported at the moment (2018-04-26)
 
   # TODO: we can special case hex result/input as an array of bytes
@@ -137,7 +137,7 @@ func parse*[bits: static[int]](input: string, T: typedesc[Stuint[bits]], radix:
 func parse*[bits: static[int]](input: string, T: typedesc[Stint[bits]], radix: static[int8] = 10): T =
   ## Parse a string and store the result in a Stint[bits] or Stuint[bits].
 
-  static: assert (radix >= 2) and radix <= 16, "Only base from 2..16 are supported"
+  static: doAssert (radix >= 2) and radix <= 16, "Only base from 2..16 are supported"
   # TODO: use static[range[2 .. 16]], not supported at the moment (2018-04-26)
 
   # TODO: we can special case hex result/input as an array of bytes
@@ -152,7 +152,7 @@ func parse*[bits: static[int]](input: string, T: typedesc[Stint[bits]], radix: s
     no_overflow: Stuint[bits]
 
   if input[curr] == '-':
-    assert radix == 10, "Negative numbers are only supported with base 10 input."
+    doAssert radix == 10, "Negative numbers are only supported with base 10 input."
     isNeg = true
     inc curr
   else:
@@ -186,7 +186,7 @@ func toString*[bits: static[int]](num: StUint[bits], radix: static[uint8] = 10):
   ##   - they are prefixed with "-" for base 10.
   ##   - if not base 10, they are returned raw in two-complement form.
 
-  static: assert (radix >= 2) and radix <= 16, "Only base from 2..16 are supported"
+  static: doAssert (radix >= 2) and radix <= 16, "Only base from 2..16 are supported"
   # TODO: use static[range[2 .. 16]], not supported at the moment (2018-04-26)
 
   const hexChars = "0123456789abcdef"
@@ -209,7 +209,7 @@ func toString*[bits: static[int]](num: Stint[bits], radix: static[int8] = 10): s
   ##   - they are prefixed with "-" for base 10.
   ##   - if not base 10, they are returned raw in two-complement form.
 
-  static: assert (radix >= 2) and radix <= 16, "Only base from 2..16 are supported"
+  static: doAssert (radix >= 2) and radix <= 16, "Only base from 2..16 are supported"
   # TODO: use static[range[2 .. 16]], not supported at the moment (2018-04-26)
 
   const hexChars = "0123456789abcdef"
@@ -287,9 +287,9 @@ proc initFromBytesBE*[bits: static[int]](val: var Stuint[bits], ba: openarray[by
   const N = bits div 8
 
   when not allowPadding:
-    assert(ba.len == N)
+    doAssert(ba.len == N)
   else:
-    assert ba.len <= N
+    doAssert ba.len <= N
 
   {.pragma: restrict, codegenDecl: "$# __restrict $#".}
   let r_ptr {.restrict.} = cast[ptr array[N, byte]](val.addr)
diff --git a/stint/modular_arithmetic.nim b/stint/modular_arithmetic.nim
index 773904d..2b0cc40 100644
--- a/stint/modular_arithmetic.nim
+++ b/stint/modular_arithmetic.nim
@@ -13,8 +13,8 @@ func addmod_internal(a, b, m: Stuint): Stuint {.inline.}=
   ## Modular addition
   ## ⚠⚠ Assume a < m and b < m
 
-  assert a < m
-  assert b < m
+  doAssert a < m
+  doAssert b < m
 
   # We don't do a_m + b_m directly to avoid overflows
   let b_from_m = m - b
@@ -27,8 +27,8 @@ func submod_internal(a, b, m: Stuint): Stuint {.inline.}=
   ## Modular substraction
   ## ⚠⚠ Assume a < m and b < m
 
-  assert a < m
-  assert b < m
+  doAssert a < m
+  doAssert b < m
 
   # We don't do a_m - b_m directly to avoid underflows
   if a >= b:
@@ -40,7 +40,7 @@ func doublemod_internal(a, m: Stuint): Stuint {.inline.}=
   ## Double a modulo m. Assume a < m
   ## Internal proc - used in mulmod
 
-  assert a < m
+  doAssert a < m
 
   result = a
   if a >= m - a:
@@ -51,8 +51,8 @@ func mulmod_internal(a, b, m: Stuint): Stuint {.inline.}=
   ## Does (a * b) mod m. Assume a < m and b < m
   ## Internal proc - used in powmod
 
-  assert a < m
-  assert b < m
+  doAssert a < m
+  doAssert b < m
 
   var (a, b) = (a, b)
 
@@ -69,7 +69,7 @@ func powmod_internal(a, b, m: Stuint): Stuint {.inline.}=
   ## Compute ``(a ^ b) mod m``, assume a < m
   ## Internal proc
 
-  assert a < m
+  doAssert a < m
 
   var (a, b) = (a, b)
   result = one(type a)
diff --git a/stint/private/uint_div.nim b/stint/private/uint_div.nim
index ba86cee..70b3ae8 100644
--- a/stint/private/uint_div.nim
+++ b/stint/private/uint_div.nim
@@ -122,7 +122,7 @@ proc div3n2n[T: SomeUnsignedInt](
 
 func div2n1n(q, r: var UintImpl, ah, al, b: UintImpl) =
 
-  # assert countLeadingZeroBits(b) == 0, "Divisor was not normalized"
+  # doAssert countLeadingZeroBits(b) == 0, "Divisor was not normalized"
 
   var s: UintImpl
   div3n2n(q.hi, s, ah.hi, ah.lo, al.hi, b)
@@ -130,7 +130,7 @@ func div2n1n(q, r: var UintImpl, ah, al, b: UintImpl) =
 
 func div2n1n[T: SomeunsignedInt](q, r: var T, n_hi, n_lo, d: T) =
 
-  # assert countLeadingZeroBits(d) == 0, "Divisor was not normalized"
+  # doAssert countLeadingZeroBits(d) == 0, "Divisor was not normalized"
 
   const
     size = bitsof(q)
@@ -170,7 +170,7 @@ func div2n1n[T: SomeunsignedInt](q, r: var T, n_hi, n_lo, d: T) =
 
 func divmodBZ[T](x, y: UintImpl[T], q, r: var UintImpl[T])=
 
-  assert y.isZero.not() # This should be checked on release mode in the divmod caller proc
+  doAssert y.isZero.not() # This should be checked on release mode in the divmod caller proc
 
   if y.hi.isZero:
     # Shortcut if divisor is smaller than half the size of the type
@@ -207,7 +207,7 @@ func divmodBS(x, y: UintImpl, q, r: var UintImpl) =
   ## Division for multi-precision unsigned uint
   ## Implementation through binary shift division
 
-  assert y.isZero.not() # This should be checked on release mode in the divmod caller proc
+  doAssert y.isZero.not() # This should be checked on release mode in the divmod caller proc
 
   type SubTy = type x.lo
 
diff --git a/tests/test_io.nim b/tests/test_io.nim
index 32e4362..3d29c4e 100644
--- a/tests/test_io.nim
+++ b/tests/test_io.nim
@@ -200,7 +200,7 @@ suite "Testing conversion functions: Hex, Bytes, Endianness using secp256k1 curv
   #     sig = ecc.sign(msghash)
   #     print("    sig='{}',".format(encode_hex(sig)))
   #     print("    raw_sig='{}')".format(crypto._decode_sig(sig)))
-  #     assert crypto.ecdsa_recover(msghash, sig) == pubkey
+  #     doAssert crypto.ecdsa_recover(msghash, sig) == pubkey
   # """
 
   type
diff --git a/tests/test_uint_bitwise.nim b/tests/test_uint_bitwise.nim
index 8014d8d..de94987 100644
--- a/tests/test_uint_bitwise.nim
+++ b/tests/test_uint_bitwise.nim
@@ -14,7 +14,7 @@ suite "Testing unsigned int bitwise operations":
 
   let b = a * a
   let z = 10000'u16
-  assert cast[uint16](b) == z, "Test cannot proceed, something is wrong with the multiplication implementation"
+  doAssert cast[uint16](b) == z, "Test cannot proceed, something is wrong with the multiplication implementation"
 
 
   let u = 10000.stuint(64)