diff --git a/asg/src/const_value.rs b/asg/src/const_value.rs
index 2316604925..f093a65559 100644
--- a/asg/src/const_value.rs
+++ b/asg/src/const_value.rs
@@ -186,7 +186,7 @@ macro_rules! const_int_bimap {
 impl ConstInt {
     const_int_op!(raw_value, String, x, format!("{}", x));
 
-    const_int_map!(value_negate, x, x.overflowing_neg().0);
+    const_int_map!(value_negate, x, x.checked_neg()?);
 
     const_int_map!(value_bit_negate, x, !x);
 
@@ -267,61 +267,18 @@ impl ConstInt {
         Type::Integer(self.get_int_type())
     }
 
-    fn parse_signed(int_type: &IntegerType, raw: u128) -> Option<ConstInt> {
-        Some(match int_type {
-            IntegerType::I8 => ConstInt::I8(raw.try_into().ok()?),
-            IntegerType::I16 => ConstInt::I16(raw.try_into().ok()?),
-            IntegerType::I32 => ConstInt::I32(raw.try_into().ok()?),
-            IntegerType::I64 => ConstInt::I64(raw.try_into().ok()?),
-            IntegerType::I128 => ConstInt::I128(raw.try_into().ok()?),
-            _ => panic!("illegal type passed to parse_signed"),
-        })
-    }
-
     pub fn parse(int_type: &IntegerType, value: &str, span: &Span) -> Result<ConstInt, AsgConvertError> {
-        let raw: u128 = value.parse().map_err(|_| AsgConvertError::invalid_int(&value, span))?;
         Ok(match int_type {
-            // IntegerType::I8 => ConstInt::I8(raw.try_into().map_err(|_| AsgConvertError::overflowed_const_int(&value, span))?),
-            // IntegerType::I16 => ConstInt::I16(raw.try_into().map_err(|_| AsgConvertError::overflowed_const_int(&value, span))?),
-            // IntegerType::I32 => ConstInt::I32(raw.try_into().map_err(|_| AsgConvertError::overflowed_const_int(&value, span))?),
-            // IntegerType::I64 => ConstInt::I64(raw.try_into().map_err(|_| AsgConvertError::overflowed_const_int(&value, span))?),
-            // IntegerType::I128 => ConstInt::I128(raw.try_into().map_err(|_| AsgConvertError::overflowed_const_int(&value, span))?),
-            IntegerType::U8 => ConstInt::U8(
-                raw.try_into()
-                    .map_err(|_| AsgConvertError::overflowed_const_int(&value, span))?,
-            ),
-            IntegerType::U16 => ConstInt::U16(
-                raw.try_into()
-                    .map_err(|_| AsgConvertError::overflowed_const_int(&value, span))?,
-            ),
-            IntegerType::U32 => ConstInt::U32(
-                raw.try_into()
-                    .map_err(|_| AsgConvertError::overflowed_const_int(&value, span))?,
-            ),
-            IntegerType::U64 => ConstInt::U64(
-                raw.try_into()
-                    .map_err(|_| AsgConvertError::overflowed_const_int(&value, span))?,
-            ),
-            IntegerType::U128 => ConstInt::U128(
-                raw.try_into()
-                    .map_err(|_| AsgConvertError::overflowed_const_int(&value, span))?,
-            ),
-            signed_type => {
-                if let Some(parsed) = Self::parse_signed(signed_type, raw) {
-                    parsed
-                } else if let Some(_parsed) = Self::parse_signed(signed_type, raw - 1) {
-                    match int_type {
-                        IntegerType::I8 => ConstInt::I8(raw as i8),
-                        IntegerType::I16 => ConstInt::I16(raw as i16),
-                        IntegerType::I32 => ConstInt::I32(raw as i32),
-                        IntegerType::I64 => ConstInt::I64(raw as i64),
-                        IntegerType::I128 => ConstInt::I128(raw as i128),
-                        _ => panic!("illegal type passed to parse_signed"),
-                    }
-                } else {
-                    return Err(AsgConvertError::overflowed_const_int(&value, span));
-                }
-            }
+            IntegerType::I8 => ConstInt::I8(value.parse().map_err(|_| AsgConvertError::invalid_int(&value, span))?),
+            IntegerType::I16 => ConstInt::I16(value.parse().map_err(|_| AsgConvertError::invalid_int(&value, span))?),
+            IntegerType::I32 => ConstInt::I32(value.parse().map_err(|_| AsgConvertError::invalid_int(&value, span))?),
+            IntegerType::I64 => ConstInt::I64(value.parse().map_err(|_| AsgConvertError::invalid_int(&value, span))?),
+            IntegerType::I128 => ConstInt::I128(value.parse().map_err(|_| AsgConvertError::invalid_int(&value, span))?),
+            IntegerType::U8 => ConstInt::U8(value.parse().map_err(|_| AsgConvertError::invalid_int(&value, span))?),
+            IntegerType::U16 => ConstInt::U16(value.parse().map_err(|_| AsgConvertError::invalid_int(&value, span))?),
+            IntegerType::U32 => ConstInt::U32(value.parse().map_err(|_| AsgConvertError::invalid_int(&value, span))?),
+            IntegerType::U64 => ConstInt::U64(value.parse().map_err(|_| AsgConvertError::invalid_int(&value, span))?),
+            IntegerType::U128 => ConstInt::U128(value.parse().map_err(|_| AsgConvertError::invalid_int(&value, span))?),
         })
     }
 }
diff --git a/asg/src/error/mod.rs b/asg/src/error/mod.rs
index 1cb3ef346e..87040a58fa 100644
--- a/asg/src/error/mod.rs
+++ b/asg/src/error/mod.rs
@@ -244,10 +244,6 @@ impl AsgConvertError {
         Self::new_from_span(format!("failed to parse int value '{}'", value), span)
     }
 
-    pub fn overflowed_const_int(value: &str, span: &Span) -> Self {
-        Self::new_from_span(format!("const int value is overflowed for type '{}'", value), span)
-    }
-
     pub fn unsigned_negation(span: &Span) -> Self {
         Self::new_from_span("cannot negate unsigned integer".to_string(), span)
     }
diff --git a/ast/src/common/span.rs b/ast/src/common/span.rs
index 33879b364f..1f672f9889 100644
--- a/ast/src/common/span.rs
+++ b/ast/src/common/span.rs
@@ -67,6 +67,7 @@ impl std::ops::Add for &Span {
 impl std::ops::Add for Span {
     type Output = Self;
 
+    #[allow(clippy::comparison_chain)]
     fn add(self, other: Self) -> Self {
         if self.line_start == other.line_stop {
             Span {
diff --git a/ast/src/types/integer_type.rs b/ast/src/types/integer_type.rs
index 2319c51769..579ca2c6c0 100644
--- a/ast/src/types/integer_type.rs
+++ b/ast/src/types/integer_type.rs
@@ -42,10 +42,7 @@ pub enum IntegerType {
 impl IntegerType {
     pub fn is_signed(&self) -> bool {
         use IntegerType::*;
-        match self {
-            I8 | I16 | I32 | I64 | I128 => true,
-            _ => false,
-        }
+        matches!(self, I8 | I16 | I32 | I64 | I128)
     }
 }
 
diff --git a/parser/src/parser/expression.rs b/parser/src/parser/expression.rs
index 299368b5c3..257cb30852 100644
--- a/parser/src/parser/expression.rs
+++ b/parser/src/parser/expression.rs
@@ -365,14 +365,25 @@ impl ParserContext {
         }
         let mut inner = self.parse_access_expression()?;
         for op in ops.into_iter().rev() {
+            let operation = match op.token {
+                Token::Not => UnaryOperation::Not,
+                Token::Minus => UnaryOperation::Negate,
+                Token::BitNot => UnaryOperation::BitNot,
+                _ => unimplemented!(),
+            };
+            // hack for const signed integer overflow issues
+            if matches!(operation, UnaryOperation::Negate) {
+                if let Expression::Value(ValueExpression::Integer(type_, value, span)) = inner {
+                    inner = Expression::Value(ValueExpression::Integer(type_, format!("-{}", value), &op.span + &span));
+                    continue;
+                } else if let Expression::Value(ValueExpression::Implicit(value, span)) = inner {
+                    inner = Expression::Value(ValueExpression::Implicit(format!("-{}", value), &op.span + &span));
+                    continue;
+                }
+            }
             inner = Expression::Unary(UnaryExpression {
                 span: &op.span + inner.span(),
-                op: match op.token {
-                    Token::Not => UnaryOperation::Not,
-                    Token::Minus => UnaryOperation::Negate,
-                    Token::BitNot => UnaryOperation::BitNot,
-                    _ => unimplemented!(),
-                },
+                op: operation,
                 inner: Box::new(inner),
             });
         }