diff --git a/implementations/rust/preserves/src/value/signed_integer.rs b/implementations/rust/preserves/src/value/signed_integer.rs
index 4d38dd7..7dde714 100644
--- a/implementations/rust/preserves/src/value/signed_integer.rs
+++ b/implementations/rust/preserves/src/value/signed_integer.rs
@@ -144,3 +144,31 @@ impl<'a> From<&'a SignedInteger> for BigInt {
         }
     }
 }
+
+impl TryFrom<&SignedInteger> for i64 {
+    type Error = ();
+    fn try_from(v: &SignedInteger) -> Result<Self, Self::Error> {
+        i128::try_from(v)?.try_into().map_err(|_| ())
+    }
+}
+
+impl TryFrom<&SignedInteger> for u64 {
+    type Error = ();
+    fn try_from(v: &SignedInteger) -> Result<Self, Self::Error> {
+        u128::try_from(v)?.try_into().map_err(|_| ())
+    }
+}
+
+impl TryFrom<&SignedInteger> for isize {
+    type Error = ();
+    fn try_from(v: &SignedInteger) -> Result<Self, Self::Error> {
+        i128::try_from(v)?.try_into().map_err(|_| ())
+    }
+}
+
+impl TryFrom<&SignedInteger> for usize {
+    type Error = ();
+    fn try_from(v: &SignedInteger) -> Result<Self, Self::Error> {
+        u128::try_from(v)?.try_into().map_err(|_| ())
+    }
+}