diff --git a/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/AddSubTransformer.kt b/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/AddSubTransformer.kt
index 99592dd0f2..ca15f65e1d 100644
--- a/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/AddSubTransformer.kt
+++ b/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/AddSubTransformer.kt
@@ -3,6 +3,8 @@ package dev.openrs2.deob.ast.transform
 import com.github.javaparser.ast.CompilationUnit
 import com.github.javaparser.ast.expr.BinaryExpr
 import com.github.javaparser.ast.expr.Expression
+import com.github.javaparser.ast.expr.IntegerLiteralExpr
+import com.github.javaparser.ast.expr.LongLiteralExpr
 import com.github.javaparser.ast.expr.UnaryExpr
 import dev.openrs2.deob.ast.util.hasSideEffects
 import dev.openrs2.deob.ast.util.isString
@@ -45,8 +47,16 @@ class AddSubTransformer : Transformer() {
     private fun Expression.isNegative(): Boolean {
         return when {
             isUnaryExpr -> asUnaryExpr().operator == UnaryExpr.Operator.MINUS
-            isIntegerLiteralExpr -> asIntegerLiteralExpr().asInt() < 0
-            isLongLiteralExpr -> asLongLiteralExpr().asLong() < 0
+            isIntegerLiteralExpr -> when (val n = asIntegerLiteralExpr().asNumber()) {
+                IntegerLiteralExpr.MAX_31_BIT_UNSIGNED_VALUE_AS_LONG -> false
+                is Int -> n < 0
+                else -> error("Invalid IntegerLiteralExpr type")
+            }
+            isLongLiteralExpr -> when (val n = asLongLiteralExpr().asNumber()) {
+                LongLiteralExpr.MAX_63_BIT_UNSIGNED_VALUE_AS_BIG_INTEGER -> false
+                is Long -> n < 0
+                else -> error("Invalid LongLiteralExpr type")
+            }
             else -> false
         }
     }
diff --git a/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/BitMaskTransformer.kt b/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/BitMaskTransformer.kt
index e8e1701ba3..1b01f4da35 100644
--- a/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/BitMaskTransformer.kt
+++ b/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/BitMaskTransformer.kt
@@ -3,6 +3,8 @@ package dev.openrs2.deob.ast.transform
 import com.github.javaparser.ast.CompilationUnit
 import com.github.javaparser.ast.expr.BinaryExpr
 import com.github.javaparser.ast.expr.IntegerLiteralExpr
+import dev.openrs2.deob.ast.util.checkedAsInt
+import dev.openrs2.deob.ast.util.checkedAsLong
 import dev.openrs2.deob.ast.util.createLong
 import dev.openrs2.deob.ast.util.isIntegerOrLongLiteral
 import dev.openrs2.deob.ast.util.walk
@@ -27,9 +29,9 @@ class BitMaskTransformer : Transformer() {
                 return@walk
             }
 
-            val shamt = shamtExpr.asIntegerLiteralExpr().asInt()
+            val shamt = shamtExpr.asIntegerLiteralExpr().checkedAsInt()
             if (maskExpr.isIntegerLiteralExpr) {
-                var mask = maskExpr.asIntegerLiteralExpr().asInt()
+                var mask = maskExpr.asIntegerLiteralExpr().checkedAsInt()
 
                 mask = when (shiftOp) {
                     BinaryExpr.Operator.SIGNED_RIGHT_SHIFT -> mask shr shamt
@@ -37,9 +39,9 @@ class BitMaskTransformer : Transformer() {
                     else -> error("Invalid shiftOp")
                 }
 
-                maskExpr = IntegerLiteralExpr(mask)
+                maskExpr = IntegerLiteralExpr(mask.toString())
             } else {
-                var mask = maskExpr.asLongLiteralExpr().asLong()
+                var mask = maskExpr.asLongLiteralExpr().checkedAsLong()
 
                 mask = when (shiftOp) {
                     BinaryExpr.Operator.SIGNED_RIGHT_SHIFT -> mask shr shamt
diff --git a/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/ComplementTransformer.kt b/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/ComplementTransformer.kt
index 94778153e6..f80a9eac4f 100644
--- a/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/ComplementTransformer.kt
+++ b/deob-ast/src/main/java/dev/openrs2/deob/ast/transform/ComplementTransformer.kt
@@ -5,6 +5,8 @@ import com.github.javaparser.ast.expr.BinaryExpr
 import com.github.javaparser.ast.expr.Expression
 import com.github.javaparser.ast.expr.IntegerLiteralExpr
 import com.github.javaparser.ast.expr.UnaryExpr
+import dev.openrs2.deob.ast.util.checkedAsInt
+import dev.openrs2.deob.ast.util.checkedAsLong
 import dev.openrs2.deob.ast.util.createLong
 import dev.openrs2.deob.ast.util.isIntegerOrLongLiteral
 import dev.openrs2.deob.ast.util.walk
@@ -49,8 +51,8 @@ class ComplementTransformer : Transformer() {
         private fun Expression.complement(): Expression {
             return when {
                 isUnaryExpr -> asUnaryExpr().expression
-                isIntegerLiteralExpr -> IntegerLiteralExpr(asIntegerLiteralExpr().asInt().inv())
-                isLongLiteralExpr -> createLong(asLongLiteralExpr().asLong().inv())
+                isIntegerLiteralExpr -> IntegerLiteralExpr(asIntegerLiteralExpr().checkedAsInt().inv().toString())
+                isLongLiteralExpr -> createLong(asLongLiteralExpr().checkedAsLong().inv())
                 else -> throw IllegalArgumentException()
             }
         }
diff --git a/deob-ast/src/main/java/dev/openrs2/deob/ast/util/ExprUtils.kt b/deob-ast/src/main/java/dev/openrs2/deob/ast/util/ExprUtils.kt
index 3b44aa872e..2017170938 100644
--- a/deob-ast/src/main/java/dev/openrs2/deob/ast/util/ExprUtils.kt
+++ b/deob-ast/src/main/java/dev/openrs2/deob/ast/util/ExprUtils.kt
@@ -7,6 +7,22 @@ import com.github.javaparser.ast.expr.IntegerLiteralExpr
 import com.github.javaparser.ast.expr.LongLiteralExpr
 import com.github.javaparser.ast.expr.UnaryExpr
 
+fun IntegerLiteralExpr.checkedAsInt(): Int {
+    val n = asNumber()
+    if (n !is Int) {
+        error("Invalid IntegerLiteralExpr type")
+    }
+    return n
+}
+
+fun LongLiteralExpr.checkedAsLong(): Long {
+    val n = asNumber()
+    if (n !is Long) {
+        error("Invalid LongLiteralExpr type")
+    }
+    return n
+}
+
 fun Expression.isIntegerOrLongLiteral(): Boolean {
     return isIntegerLiteralExpr || isLongLiteralExpr
 }
@@ -19,9 +35,17 @@ fun Expression.negate(): Expression {
     return if (isUnaryExpr && asUnaryExpr().operator == UnaryExpr.Operator.MINUS) {
         asUnaryExpr().expression.clone()
     } else if (isIntegerLiteralExpr) {
-        IntegerLiteralExpr(-asIntegerLiteralExpr().asInt())
+        when (val n = asIntegerLiteralExpr().asNumber()) {
+            IntegerLiteralExpr.MAX_31_BIT_UNSIGNED_VALUE_AS_LONG -> IntegerLiteralExpr(Integer.MIN_VALUE.toString())
+            is Int -> IntegerLiteralExpr((-n.toInt()).toString())
+            else -> error("Invalid IntegerLiteralExpr type")
+        }
     } else if (isLongLiteralExpr) {
-        createLong(-asLongLiteralExpr().asLong())
+        when (val n = asLongLiteralExpr().asNumber()) {
+            LongLiteralExpr.MAX_63_BIT_UNSIGNED_VALUE_AS_BIG_INTEGER -> createLong(Long.MIN_VALUE)
+            is Long -> createLong(-n)
+            else -> error("Invalid LongLiteralExpr type")
+        }
     } else {
         throw IllegalArgumentException()
     }