diff --git a/Lib/test/test_math.py b/Lib/test/test_math.py
index 6b421bc55..c90c063cd 100644
--- a/Lib/test/test_math.py
+++ b/Lib/test/test_math.py
@@ -1063,8 +1063,6 @@ class MathTests(unittest.TestCase):
         self.assertEqual(math.log(INF), INF)
         self.assertTrue(math.isnan(math.log(NAN)))
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def testLog1p(self):
         self.assertRaises(TypeError, math.log1p)
         for n in [2, 2**90, 2**300]:
diff --git a/stdlib/src/math.rs b/stdlib/src/math.rs
index b2437563a..c8e0c12b5 100644
--- a/stdlib/src/math.rs
+++ b/stdlib/src/math.rs
@@ -145,8 +145,13 @@ mod math {
     }
 
     #[pyfunction]
-    fn log1p(x: ArgIntoFloat) -> f64 {
-        (x.to_f64() + 1.0).ln()
+    fn log1p(x: ArgIntoFloat, vm: &VirtualMachine) -> PyResult<f64> {
+        let x = x.to_f64();
+        if x.is_nan() || x > -1.0_f64 {
+            Ok((x + 1.0_f64).ln())
+        } else {
+            Err(vm.new_value_error("math domain error".to_owned()))
+        }
     }
 
     #[pyfunction]