diff --git a/stdlib/cmath.pyi b/stdlib/cmath.pyi
index aed4c63862fe..fdf8ae7bfed8 100644
--- a/stdlib/cmath.pyi
+++ b/stdlib/cmath.pyi
@@ -9,6 +9,7 @@ nan: Final[float]
 nanj: Final[complex]
 tau: Final[float]
 
+_F: TypeAlias = SupportsFloat | SupportsIndex
 _C: TypeAlias = SupportsFloat | SupportsComplex | SupportsIndex | complex
 
 def acos(z: _C, /) -> complex: ...
@@ -27,7 +28,7 @@ def log(z: _C, base: _C = ..., /) -> complex: ...
 def log10(z: _C, /) -> complex: ...
 def phase(z: _C, /) -> float: ...
 def polar(z: _C, /) -> tuple[float, float]: ...
-def rect(r: float, phi: float, /) -> complex: ...
+def rect(r: _F, phi: _F, /) -> complex: ...
 def sin(z: _C, /) -> complex: ...
 def sinh(z: _C, /) -> complex: ...
 def sqrt(z: _C, /) -> complex: ...