diff --git a/rebound/particle.pyi b/rebound/particle.pyi
index b9810a5..305277e 100644
--- a/rebound/particle.pyi
+++ b/rebound/particle.pyi
@@ -37,11 +37,11 @@ class Particle(Structure):
 
     def copy(self) -> Particle: ...
 
-    def calculate_orbit(self, primary: Optional[Particle], G: Optional[float]): ...
+    def calculate_orbit(self, primary: Optional[Particle], G: Optional[float]) -> Orbit: ...
 
     def sample_orbit(self, Npts: int, primary: Optional[Particle], trailing: bool,
                      timespan: Optional[float], useTrueAnomaly: Optional[bool],
-                     duplicateEndpoint: Optional[bool]): ...
+                     duplicateEndpoint: Optional[bool]): ... #TODO: return value
 
     def __pow__(self, other: Particle) -> Particle: ...
 
@@ -170,7 +170,7 @@ class Particle(Structure):
     def orbit(self) -> Orbit: ...
 
     @property
-    def jacobi_com(self): ...  #TODO: correct tpying
+    def jacobi_com(self): ...  #TODO: correct typing
 
     @property
     def hash(self) -> c_uint32: ...
diff --git a/rebound/simulation.pyi b/rebound/simulation.pyi
index f74f4e0..167b325 100644
--- a/rebound/simulation.pyi
+++ b/rebound/simulation.pyi
@@ -256,7 +256,7 @@ class Simulation(Structure):
     # _extras_cleanup: CFUNCTYPE(None, _Pointer[Simulation])
     extras: c_void_p
 
-    def __new__(cls, *args: Any, **kw: Any): ...
+    def __new__(cls, *args: Any, **kw: Any)->Simulation: ...
 
     def __init__(self) -> None: ...