diff --git a/infrahub_sdk/timestamp.py b/infrahub_sdk/timestamp.py
index ffeaf214..a9a56278 100644
--- a/infrahub_sdk/timestamp.py
+++ b/infrahub_sdk/timestamp.py
@@ -153,7 +153,7 @@ def add(
         nanoseconds: int = 0,
         disambiguate: Literal["compatible"] = "compatible",
     ) -> Timestamp:
-        return Timestamp(
+        return self.__class__(
             self._obj.add(
                 years=years,
                 months=months,
@@ -183,7 +183,7 @@ def subtract(
         nanoseconds: int = 0,
         disambiguate: Literal["compatible"] = "compatible",
     ) -> Timestamp:
-        return Timestamp(
+        return self.__class__(
             self._obj.subtract(
                 years=years,
                 months=months,