diff --git a/KaitaiStream.ts b/KaitaiStream.ts
index 2dbc67a..a374906 100644
--- a/KaitaiStream.ts
+++ b/KaitaiStream.ts
@@ -1040,8 +1040,6 @@ namespace KaitaiStream {
      */
     public constructor(bytesReq: number, bytesAvail: number) {
       super("requested " + bytesReq + " bytes, but only " + bytesAvail + " bytes available");
-      // Workaround https://www.typescriptlang.org/docs/handbook/2/classes.html#inheriting-built-in-types
-      Object.setPrototypeOf(this, KaitaiStream.EOFError.prototype);
       this.bytesReq = bytesReq;
       this.bytesAvail = bytesAvail;
     }
@@ -1061,8 +1059,6 @@ namespace KaitaiStream {
      */
     public constructor(expected: any, actual: any) {
       super("expected [" + expected + "], but got [" + actual + "]");
-      // Workaround https://www.typescriptlang.org/docs/handbook/2/classes.html#inheriting-built-in-types
-      Object.setPrototypeOf(this, KaitaiStream.UnexpectedDataError.prototype);
       this.expected = expected;
       this.actual = actual;
     }
@@ -1073,8 +1069,6 @@ namespace KaitaiStream {
 
     public constructor() {
       super();
-      // Workaround https://www.typescriptlang.org/docs/handbook/2/classes.html#inheriting-built-in-types
-      Object.setPrototypeOf(this, KaitaiStream.UndecidedEndiannessError.prototype);
     }
   };
 
@@ -1089,8 +1083,6 @@ namespace KaitaiStream {
      */
     public constructor(expected: any, actual: any) {
       super("not equal, expected [" + expected + "], but got [" + actual + "]");
-      // Workaround https://www.typescriptlang.org/docs/handbook/2/classes.html#inheriting-built-in-types
-      Object.setPrototypeOf(this, KaitaiStream.ValidationNotEqualError.prototype);
       this.expected = expected;
       this.actual = actual;
     }
@@ -1107,8 +1099,6 @@ namespace KaitaiStream {
      */
     public constructor(min: any, actual: any) {
       super("not in range, min [" + min + "], but got [" + actual + "]");
-      // Workaround https://www.typescriptlang.org/docs/handbook/2/classes.html#inheriting-built-in-types
-      Object.setPrototypeOf(this, KaitaiStream.ValidationLessThanError.prototype);
       this.min = min;
       this.actual = actual;
     }
@@ -1125,8 +1115,6 @@ namespace KaitaiStream {
      */
     public constructor(max: any, actual: any) {
       super("not in range, max [" + max + "], but got [" + actual + "]");
-      // Workaround https://www.typescriptlang.org/docs/handbook/2/classes.html#inheriting-built-in-types
-      Object.setPrototypeOf(this, KaitaiStream.ValidationGreaterThanError.prototype);
       this.max = max;
       this.actual = actual;
     }
@@ -1141,8 +1129,6 @@ namespace KaitaiStream {
      */
     public constructor(actual: any) {
       super("not any of the list, got [" + actual + "]");
-      // Workaround https://www.typescriptlang.org/docs/handbook/2/classes.html#inheriting-built-in-types
-      Object.setPrototypeOf(this, KaitaiStream.ValidationNotAnyOfError.prototype);
       this.actual = actual;
     }
   };
@@ -1156,8 +1142,6 @@ namespace KaitaiStream {
      */
     public constructor(actual: any) {
       super("not in the enum, got [" + actual + "]");
-      // Workaround https://www.typescriptlang.org/docs/handbook/2/classes.html#inheriting-built-in-types
-      Object.setPrototypeOf(this, KaitaiStream.ValidationNotInEnumError.prototype);
       this.actual = actual;
     }
   };
@@ -1171,8 +1155,6 @@ namespace KaitaiStream {
      */
     public constructor(actual: any) {
       super("not matching the expression, got [" + actual + "]");
-      // Workaround https://www.typescriptlang.org/docs/handbook/2/classes.html#inheriting-built-in-types
-      Object.setPrototypeOf(this, KaitaiStream.ValidationExprError.prototype);
       this.actual = actual;
     }
   };
diff --git a/package-lock.json b/package-lock.json
index ef081e1..cbe2f13 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -13,7 +13,7 @@
         "@types/node": "^24.12.0",
         "rollup": "^4.59.0",
         "tslib": "^2.8.1",
-        "typescript": "^5.9.3"
+        "typescript": "^6.0.3"
       }
     },
     "node_modules/@rollup/plugin-typescript": {
@@ -601,9 +601,9 @@
       "license": "0BSD"
     },
     "node_modules/typescript": {
-      "version": "5.9.3",
-      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.9.3.tgz",
-      "integrity": "sha512-jl1vZzPDinLr9eUt3J/t7V6FgNEw9QjvBPdysz9KfQDD41fQrC2Y4vKQdiaUpFT4bXlb1RHhLpp8wtm6M5TgSw==",
+      "version": "6.0.3",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-6.0.3.tgz",
+      "integrity": "sha512-y2TvuxSZPDyQakkFRPZHKFm+KKVqIisdg9/CZwm9ftvKXLP8NRWj38/ODjNbr43SsoXqNuAisEf1GdCxqWcdBw==",
       "dev": true,
       "license": "Apache-2.0",
       "bin": {
diff --git a/package.json b/package.json
index fcfb75a..25c7389 100644
--- a/package.json
+++ b/package.json
@@ -43,6 +43,6 @@
     "@types/node": "^24.12.0",
     "rollup": "^4.59.0",
     "tslib": "^2.8.1",
-    "typescript": "^5.9.3"
+    "typescript": "^6.0.3"
   }
 }
diff --git a/tsconfig.json b/tsconfig.json
index 6af8f75..591e65d 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -11,7 +11,7 @@
     // "disableReferencedProjectLoad": true,             /* Reduce the number of projects loaded automatically by TypeScript. */
 
     /* Language and Environment */
-    "target": "es5",                                     /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
+    "target": "es6",                                     /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
     // "lib": [],                                        /* Specify a set of bundled library declaration files that describe the target runtime environment. */
     // "jsx": "preserve",                                /* Specify what JSX code is generated. */
     // "libReplacement": true,                           /* Enable lib replacement. */
@@ -26,14 +26,14 @@
     // "moduleDetection": "auto",                        /* Control what method is used to detect module-format JS files. */
 
     /* Modules */
-    "module": "es2015",                                  /* Specify what module code is generated. */
-    // "rootDir": "./",                                  /* Specify the root folder within your source files. */
-    // "moduleResolution": "node10",                     /* Specify how TypeScript looks up a file from a given module specifier. */
+    "module": "preserve",                                /* Specify what module code is generated. */
+    "rootDir": "./",                                     /* Specify the root folder within your source files. */
+    "moduleResolution": "bundler",                       /* Specify how TypeScript looks up a file from a given module specifier. */
     // "baseUrl": "./",                                  /* Specify the base directory to resolve non-relative module names. */
     // "paths": {},                                      /* Specify a set of entries that re-map imports to additional lookup locations. */
     // "rootDirs": [],                                   /* Allow multiple folders to be treated as one when resolving modules. */
     // "typeRoots": [],                                  /* Specify multiple folders that act like './node_modules/@types'. */
-    // "types": [],                                      /* Specify type package names to be included without being referenced in a source file. */
+    "types": ["node"],                                   /* Specify type package names to be included without being referenced in a source file. */
     // "allowUmdGlobalAccess": true,                     /* Allow accessing UMD globals from modules. */
     // "moduleSuffixes": [],                             /* List of file name suffixes to search when resolving a module. */
     // "allowImportingTsExtensions": true,               /* Allow imports to include TypeScript file extensions. Requires '--moduleResolution bundler' and either '--noEmit' or '--emitDeclarationOnly' to be set. */