diff --git a/Cargo.toml b/Cargo.toml
index 632d42eb..eb4fcc50 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "customasm"
-version = "0.10.2"
+version = "0.10.3"
 edition = "2018"
 authors = ["Henrique Lorenzi <hlorenzi12@gmail.com>"]
 
diff --git a/src/expr/eval.rs b/src/expr/eval.rs
index b4edc7db..d80402ab 100644
--- a/src/expr/eval.rs
+++ b/src/expr/eval.rs
@@ -369,9 +369,12 @@ fn bigint_not(x: BigInt) -> BigInt
 {
 	let mut x_bytes = x.to_signed_bytes_le();
 	
+	if x.sign() != Sign::Minus
+		{ x_bytes.push(0); }
+	
 	for i in 0..x_bytes.len()
 		{ x_bytes[i] = !x_bytes[i]; }
-		
+	
 	BigInt::from_signed_bytes_le(&x_bytes)
 }
 
diff --git a/src/test/expr.rs b/src/test/expr.rs
index 76927fcd..a64f75eb 100644
--- a/src/test/expr.rs
+++ b/src/test/expr.rs
@@ -146,6 +146,24 @@ fn test_ops_bitmanipulation()
 	test("! 1", Pass(ExpressionValue::Integer(BigInt::from(-2))));
 	test("!-1", Pass(ExpressionValue::Integer(BigInt::from(0))));
 	
+	test("!7", Pass(ExpressionValue::Integer(BigInt::from(-8))));
+	test("!8", Pass(ExpressionValue::Integer(BigInt::from(-9))));
+	test("!9", Pass(ExpressionValue::Integer(BigInt::from(-10))));
+	test("!16", Pass(ExpressionValue::Integer(BigInt::from(-17))));
+	test("!32", Pass(ExpressionValue::Integer(BigInt::from(-33))));
+	test("!64", Pass(ExpressionValue::Integer(BigInt::from(-65))));
+	test("!128", Pass(ExpressionValue::Integer(BigInt::from(-129))));
+	test("!256", Pass(ExpressionValue::Integer(BigInt::from(-257))));
+
+	test("!-8", Pass(ExpressionValue::Integer(BigInt::from(7))));
+	test("!-9", Pass(ExpressionValue::Integer(BigInt::from(8))));
+	test("!-10", Pass(ExpressionValue::Integer(BigInt::from(9))));
+	test("!-17", Pass(ExpressionValue::Integer(BigInt::from(16))));
+	test("!-33", Pass(ExpressionValue::Integer(BigInt::from(32))));
+	test("!-65", Pass(ExpressionValue::Integer(BigInt::from(64))));
+	test("!-129", Pass(ExpressionValue::Integer(BigInt::from(128))));
+	test("!-257", Pass(ExpressionValue::Integer(BigInt::from(256))));
+	
 	test("0b1100 & 0b1010", Pass(ExpressionValue::Integer(BigInt::from(0b1000))));
 	test("0b1100 | 0b1010", Pass(ExpressionValue::Integer(BigInt::from(0b1110))));
 	test("0b1100 ^ 0b1010", Pass(ExpressionValue::Integer(BigInt::from(0b0110))));
diff --git a/web/customasm.gc.wasm b/web/customasm.gc.wasm
index c6b5e038..f6b78870 100644
Binary files a/web/customasm.gc.wasm and b/web/customasm.gc.wasm differ