diff --git a/source/ports/rs_port/src/types/metacall_value.rs b/source/ports/rs_port/src/types/metacall_value.rs
index 111dbd5908..8d14954975 100644
--- a/source/ports/rs_port/src/types/metacall_value.rs
+++ b/source/ports/rs_port/src/types/metacall_value.rs
@@ -196,6 +196,157 @@ impl MetaCallValue for f64 {
         unsafe { metacall_value_create_double(self) }
     }
 }
+
+//Equivalent to MetaCall long type.
+impl MetaCallValue for u8 {
+    fn get_metacall_id() -> metacall_value_id {
+        metacall_value_id::METACALL_LONG
+    }
+
+    fn from_metacall_raw_leak(v: *mut c_void) -> Result<Self, Box<dyn MetaCallValue>> {
+        let id = unsafe { metacall_value_id(v) };
+
+        let value_i64 = match id {
+            metacall_value_id::METACALL_SHORT => unsafe {
+                metacall_value_to_short(v) as i64
+            },
+            metacall_value_id::METACALL_INT => unsafe {
+                metacall_value_to_int(v) as i64
+            },
+            metacall_value_id::METACALL_LONG => unsafe {
+                metacall_value_to_long(v) 
+            },
+            _ => return Err(Box::new(0u8)),
+        };
+
+
+        if value_i64 < 0 || value_i64 > u8::MAX as i64 {
+            return Err(Box::new(value_i64));
+        }
+
+        Ok(value_i64 as u8)
+    }
+
+    fn into_metacall_raw(self) -> *mut c_void {
+        // safer to send as LONG (i64)
+        unsafe { metacall_value_create_long(self as i64) }
+    }
+}
+
+//Equivalent to MetaCall long type.
+impl MetaCallValue for u16 {
+    fn get_metacall_id() -> metacall_value_id {
+        metacall_value_id::METACALL_LONG
+    }
+
+    fn from_metacall_raw_leak(v: *mut c_void) -> Result<Self, Box<dyn MetaCallValue>> {
+        let id = unsafe { metacall_value_id(v) };
+
+        let value_i64 = match id {
+            metacall_value_id::METACALL_SHORT => unsafe {
+                metacall_value_to_short(v) as i64
+            },
+            metacall_value_id::METACALL_INT => unsafe {
+                metacall_value_to_int(v) as i64
+            },
+            metacall_value_id::METACALL_LONG => unsafe {
+                metacall_value_to_long(v) 
+            },
+            _ => return Err(Box::new(0u16)),
+        };
+
+
+        if value_i64 < 0 || value_i64 > u16::MAX as i64 {
+            return Err(Box::new(value_i64));
+        }
+
+        Ok(value_i64 as u16)
+    }
+
+    fn into_metacall_raw(self) -> *mut c_void {
+        // safer to send as LONG (i64)
+        unsafe { metacall_value_create_long(self as i64) }
+    }
+}
+
+//Equivalent to MetaCall long type.
+impl MetaCallValue for u32 {
+    fn get_metacall_id() -> metacall_value_id {
+        metacall_value_id::METACALL_LONG
+    }
+
+    fn from_metacall_raw_leak(v: *mut c_void) -> Result<Self, Box<dyn MetaCallValue>> {
+        let id = unsafe { metacall_value_id(v) };
+
+        let value_i64 = match id {
+            metacall_value_id::METACALL_INT => unsafe {
+                metacall_value_to_int(v) as i64
+            },
+            metacall_value_id::METACALL_LONG => unsafe {
+                metacall_value_to_long(v)
+            },
+            _ => {
+                return Err(Box::new(0u32));
+            }
+        };
+
+        if value_i64 < 0 {
+            return Err(Box::new(value_i64));
+        }
+
+        if value_i64 > u32::MAX as i64 {
+            return Err(Box::new(value_i64));
+        }
+
+        Ok(value_i64 as u32)
+    }
+
+    fn into_metacall_raw(self) -> *mut c_void {
+        // safer to send as LONG (i64)
+        unsafe { metacall_value_create_long(self as i64) }
+    }
+}
+
+// TODO:
+// MetaCall does not provide an unsigned 64-bit type. Since METACALL_LONG maps to i64, values above i64::MAX, cannot be represented safely.
+// Proper support for u64 may require: Adding i128 support in MetaCall
+// For now, u64 support is intentionally not implemented. Only emits warning when value exceeds i64::MAX
+impl MetaCallValue for u64 {
+    fn get_metacall_id() -> metacall_value_id {
+        metacall_value_id::METACALL_LONG
+    }
+
+    fn from_metacall_raw_leak(v: *mut c_void) -> Result<Self, Box<dyn MetaCallValue>> {
+        let id = unsafe { metacall_value_id(v) };
+
+        let value_i64 = match id {
+            metacall_value_id::METACALL_INT => unsafe {
+                metacall_value_to_int(v) as i64
+            },
+            metacall_value_id::METACALL_LONG => unsafe {
+                metacall_value_to_long(v)
+            },
+            _ => {
+                return Err(Box::new(0u64));
+            }
+        };
+
+        if value_i64 < 0 {
+            return Err(Box::new(value_i64));
+        }
+
+        Ok(value_i64 as u64)
+    }
+
+    fn into_metacall_raw(self) -> *mut c_void {
+        if self > i64::MAX as u64 {
+            eprintln!("Warning: u64 value exceeds i64::MAX, precision loss possible");
+        }
+
+        unsafe { metacall_value_create_long(self as i64) }
+    }
+}
+
 /// Equivalent to MetaCall string type.
 impl MetaCallValue for String {
     fn get_metacall_id() -> metacall_value_id {
diff --git a/source/ports/rs_port/tests/metacall_test.rs b/source/ports/rs_port/tests/metacall_test.rs
index 81d73511a3..895b07ad59 100644
--- a/source/ports/rs_port/tests/metacall_test.rs
+++ b/source/ports/rs_port/tests/metacall_test.rs
@@ -6,6 +6,23 @@ use metacall::{
 };
 use std::{any::Any, collections::HashMap, env, fmt::Debug};
 
+use std::sync::Once;
+
+static INIT: Once = Once::new();
+
+fn ensure_runtime() {
+    INIT.call_once(|| {
+        initialize().unwrap();
+
+        load::from_file(
+            Tag::Python,
+            ["tests/scripts/script.py"],
+            None,
+        )
+        .unwrap();
+    });
+}
+
 fn generate_test<T: MetaCallValue + PartialEq + Debug + Clone>(
     name: impl ToString,
     expected: T,
@@ -82,6 +99,73 @@ fn test_float() {
 fn test_double() {
     generate_test::<f64>("test_double", 1.2345_f64);
 }
+
+#[test]
+fn test_u8_valid() {
+    ensure_runtime();
+
+    let result = ::metacall::metacall_no_arg::<u8>("return_small_number");
+    assert_eq!(result.unwrap(), 42u8);
+}
+
+#[test]
+fn test_u8_negative() {
+    ensure_runtime();
+
+    let result = ::metacall::metacall_no_arg::<u8>("return_negative_int");
+    assert!(result.is_err(), "Negative value should not convert to u8");
+}
+
+#[test]
+fn test_u16_valid() {
+    ensure_runtime();
+
+    let result = ::metacall::metacall_no_arg::<u16>("return_small_number");
+    assert_eq!(result.unwrap(), 42u16);
+}
+
+#[test]
+fn test_u16_overflow() {
+    ensure_runtime();
+
+    let result = ::metacall::metacall_no_arg::<u16>("return_large_number");
+    assert!(result.is_err(), "Overflow should not convert to u16");
+}
+
+#[test]
+fn test_u32_overflow() {
+    ensure_runtime();
+
+    let result = ::metacall::metacall_no_arg::<u32>("return_large_number");
+    assert!(result.is_err());
+}
+
+
+#[test]
+fn test_u32_negative() {
+    ensure_runtime();
+
+    let result = ::metacall::metacall_no_arg::<u32>("return_negative_int");
+
+    assert!(result.is_err(), "Negative C int should not convert to u32");
+}
+
+#[test]
+fn test_u64_valid() {
+    ensure_runtime();
+
+    let result = ::metacall::metacall_no_arg::<u64>("return_large_number");
+    assert_eq!(result.unwrap(), i64::MAX as u64);
+}
+
+#[test]
+fn test_u64_negative() {
+    ensure_runtime();
+
+    let result = ::metacall::metacall_no_arg::<u64>("return_negative_int");
+    assert!(result.is_err(), "Negative value should not convert to u64");
+}
+
 fn test_mixed_numbers() {
     let result = ::metacall::metacall::<i64>(
         "test_mixed_numbers",
diff --git a/source/ports/rs_port/tests/scripts/script.py b/source/ports/rs_port/tests/scripts/script.py
index 507fa6cd65..2fd79c0898 100644
--- a/source/ports/rs_port/tests/scripts/script.py
+++ b/source/ports/rs_port/tests/scripts/script.py
@@ -13,4 +13,10 @@ def test_class():
 def test_object():
     return TestClass()
 def return_the_argument_py(argument):
-    return argument
\ No newline at end of file
+    return argument
+def return_small_number():
+    return 42
+def return_negative_int():
+    return -1
+def return_large_number():
+    return 9223372036854775807  # i64::MAX
\ No newline at end of file