diff --git a/CHANGELOG.md b/CHANGELOG.md
index 484150d..8ed1bbc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,10 +1,14 @@
 # JSON P3 Change Log
 
-## Version 1.3.4
+## Version 1.3.4 (unreleased)
 
 **Fixes**
 
 - Fixed decoding of JSONPath escape sequences (those found in name selectors and string literals). Previously we were relying on `JSON.parse()` to unescape strings, now we have our own `unescapeString()` function that rejects invalid codepoints and surrogate pairs. See [jsonpath-compliance-test-suite #87](https://github.com/jsonpath-standard/jsonpath-compliance-test-suite/pull/87).
+- Fixed default minimum integer boundary for JSONPath indexes and slice steps. We were off by one.
+- Fixed parsing of JSONPath integer literals with an exponent and an upper case 'e'. We now allow 'e' to be upper case.
+- Fixed handling of trailing commas in JSONPath bracketed segments. We now raise a syntax error.
+- Fixed handling of invalid JSONPath integer and float literals with extra minus signs, leading zeros or too many zeros. We now raise a syntax error in such cases.
 
 ## Version 1.3.3
 
diff --git a/src/path/environment.ts b/src/path/environment.ts
index fcf40b3..747baa6 100644
--- a/src/path/environment.ts
+++ b/src/path/environment.ts
@@ -129,7 +129,7 @@ export class JSONPathEnvironment {
   constructor(options: JSONPathEnvironmentOptions = {}) {
     this.strict = options.strict ?? true;
     this.maxIntIndex = options.maxIntIndex ?? Math.pow(2, 53) - 1;
-    this.minIntIndex = options.maxIntIndex ?? -Math.pow(2, 53) - 1;
+    this.minIntIndex = options.maxIntIndex ?? -Math.pow(2, 53) + 1;
     this.maxRecursionDepth = options.maxRecursionDepth ?? 50;
     this.nondeterministic = options.nondeterministic ?? false;
     this.keysPattern = options.keysPattern ?? /~/y;
diff --git a/src/path/lex.ts b/src/path/lex.ts
index a76bd22..1a2f433 100644
--- a/src/path/lex.ts
+++ b/src/path/lex.ts
@@ -5,7 +5,7 @@ import { Token, TokenKind } from "./token";
 
 // These regular expressions are to be used with Lexer.acceptMatchRun(),
 // which expects the sticky flag to be set.
-const exponentPattern = /e[+-]?\d+/y;
+const exponentPattern = /[eE][+-]?\d+/y;
 const functionNamePattern = /[a-z][a-z_0-9]*/y;
 const indexPattern = /-?\d+/y;
 const intPattern = /-?[0-9]+/y;
diff --git a/src/path/parse.ts b/src/path/parse.ts
index c100b84..0ccd019 100644
--- a/src/path/parse.ts
+++ b/src/path/parse.ts
@@ -304,6 +304,7 @@ export class Parser {
       if (stream.peek.kind !== TokenKind.RBRACKET) {
         stream.expectPeek(TokenKind.COMMA);
         stream.next();
+        stream.expectPeekNot(TokenKind.RBRACKET, "unexpected trailing comma");
       }
 
       stream.next();
@@ -362,7 +363,23 @@ export class Parser {
   }
 
   protected parseNumber(stream: TokenStream): NumberLiteral {
-    return new NumberLiteral(stream.current, Number(stream.current.value));
+    const value = stream.current.value;
+    if (value.startsWith("0") && value.length > 1) {
+      throw new JSONPathSyntaxError(
+        `invalid number literal '${value}'`,
+        stream.current,
+      );
+    }
+
+    const num = Number(stream.current.value);
+
+    if (isNaN(num)) {
+      throw new JSONPathSyntaxError(
+        `invalid number literal '${value}'`,
+        stream.current,
+      );
+    }
+    return new NumberLiteral(stream.current, num);
   }
 
   protected parsePrefixExpression(stream: TokenStream): PrefixExpression {
diff --git a/src/path/token.ts b/src/path/token.ts
index 4dc4de0..4e5c8a1 100644
--- a/src/path/token.ts
+++ b/src/path/token.ts
@@ -105,4 +105,11 @@ export class TokenStream {
       );
     }
   }
+
+  public expectPeekNot(kind: TokenKind, message: string): void {
+    const peeked = this.peek;
+    if (peeked.kind === kind) {
+      throw new JSONPathSyntaxError(message, peeked);
+    }
+  }
 }
diff --git a/tests/path/cts b/tests/path/cts
index b11c029..733fe52 160000
--- a/tests/path/cts
+++ b/tests/path/cts
@@ -1 +1 @@
-Subproject commit b11c0290808bd7021bd0b018cbb42fa1cc60bc7c
+Subproject commit 733fe526ceccb183ed0e3397340f2ee9feec0d67