diff --git a/README.md b/README.md
index 363e55a..566cf17 100644
--- a/README.md
+++ b/README.md
@@ -432,7 +432,7 @@ Values are denoted as displayed in the following table.
 |------------|---------|
 | `Value::String` | `"abc"`, `""`, `"a\"b\\c"` |
 | `Value::Boolean` | `true`, `false` |
-| `Value::Int` | `3`, `-9`, `0`, `135412`, `0xfe02`, `-0x1e` |
+| `Value::Int` | `3`, `-9`, `0`, `135412`, `0xfe02`, `-0X1e`, `$fe` |
 | `Value::Float` | `3.`, `.35`, `1.00`, `0.5`, `123.554`, `23e4`, `-2e-3`, `3.54e+2` |
 | `Value::Tuple` | `(3, 55.0, false, ())`, `(1, 2)` |
 | `Value::Empty` | `()` |
diff --git a/src/lib.rs b/src/lib.rs
index 763e94b..e80f395 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -413,7 +413,7 @@
 //! |------------|---------|
 //! | `Value::String` | `"abc"`, `""`, `"a\"b\\c"` |
 //! | `Value::Boolean` | `true`, `false` |
-//! | `Value::Int` | `3`, `-9`, `0`, `135412`, `0xfe02`, `-0x1e` |
+//! | `Value::Int` | `3`, `-9`, `0`, `135412`, `0xfe02`, `-0X1e`, `$fe` |
 //! | `Value::Float` | `3.`, `.35`, `1.00`, `0.5`, `123.554`, `23e4`, `-2e-3`, `3.54e+2` |
 //! | `Value::Tuple` | `(3, 55.0, false, ())`, `(1, 2)` |
 //! | `Value::Empty` | `()` |
diff --git a/src/token/mod.rs b/src/token/mod.rs
index ea22890..92e7521 100644
--- a/src/token/mod.rs
+++ b/src/token/mod.rs
@@ -480,7 +480,11 @@ pub(crate) fn tokenize(string: &str) -> EvalexprResult<Vec<Token>> {
 }
 
 fn parse_dec_or_hex(literal: &str) -> Result<IntType, std::num::ParseIntError> {
-    if let Some(literal) = literal.strip_prefix("0x") {
+    if let Some(literal) = literal.strip_prefix("0x").or_else(|| {
+        literal
+            .strip_prefix("0X")
+            .or_else(|| literal.strip_prefix('$'))
+    }) {
         IntType::from_str_radix(literal, 16)
     } else {
         IntType::from_str_radix(literal, 10)
diff --git a/tests/integration.rs b/tests/integration.rs
index 695056b..5cd34a7 100644
--- a/tests/integration.rs
+++ b/tests/integration.rs
@@ -2316,6 +2316,9 @@ fn test_hex() {
     assert_eq!(eval("0x3"), Ok(Value::Int(3)));
     assert_eq!(eval("0xFF"), Ok(Value::Int(255)));
     assert_eq!(eval("-0xFF"), Ok(Value::Int(-255)));
+    assert_eq!(eval("0XFF"), Ok(Value::Int(255)));
+    assert_eq!(eval("$fe"), Ok(Value::Int(254)));
+    assert!(eval("$xy").is_err());
     assert_eq!(
         eval("0x"),
         // The "VariableIdentifierNotFound" error is what evalexpr currently returns,