diff --git a/src/function/builtin.rs b/src/function/builtin.rs
index 95aecda..639584e 100644
--- a/src/function/builtin.rs
+++ b/src/function/builtin.rs
@@ -78,9 +78,6 @@ pub fn builtin_function(identifier: &str) -> Option<Function> {
         "math::cbrt" => simple_math!(cbrt),
         // Hypotenuse
         "math::hypot" => simple_math!(hypot, 2),
-        // Absolute
-        "math::abs" => simple_math!(abs),
-        // Rounding
         "floor" => simple_math!(floor),
         "round" => simple_math!(round),
         "ceil" => simple_math!(ceil),
@@ -89,6 +86,14 @@ pub fn builtin_function(identifier: &str) -> Option<Function> {
         "math::is_finite" => float_is(FloatType::is_finite),
         "math::is_infinite" => float_is(FloatType::is_infinite),
         "math::is_normal" => float_is(FloatType::is_normal),
+        // Absolute
+        "math::abs" => Some(Function::new(|argument| {
+            match argument {
+                Value::Float(num) => Ok(Value::Float(num.abs())),
+                Value::Int(num) => Ok(Value::Int(num.abs())),
+                _ => Err(EvalexprError::ExpectedNumber { actual: argument.clone() }),
+            }
+        })),
         // Other
         "typeof" => Some(Function::new(move |argument| {
             Ok(match argument {
diff --git a/tests/integration.rs b/tests/integration.rs
index ab0bfe4..2665362 100644
--- a/tests/integration.rs
+++ b/tests/integration.rs
@@ -364,8 +364,10 @@ fn test_builtin_functions() {
         Ok(Value::Float((8.2 as FloatType).hypot(1.1)))
     );
     // Absolute
-    assert_eq!(eval("math::abs(15)"), Ok(Value::Float(15.0)));
-    assert_eq!(eval("math::abs(-15)"), Ok(Value::Float(15.0)));
+    assert_eq!(eval("math::abs(15.4)"), Ok(Value::Float(15.4)));
+    assert_eq!(eval("math::abs(-15.4)"), Ok(Value::Float(15.4)));
+    assert_eq!(eval("math::abs(15)"), Ok(Value::Int(15)));
+    assert_eq!(eval("math::abs(-15)"), Ok(Value::Int(15)));
     // Rounding
     assert_eq!(eval("floor(1.1)"), Ok(Value::Float(1.0)));
     assert_eq!(eval("floor(1.9)"), Ok(Value::Float(1.0)));