diff --git a/src/jimgw/transforms.py b/src/jimgw/transforms.py
index b201f6f8..f8e128b7 100644
--- a/src/jimgw/transforms.py
+++ b/src/jimgw/transforms.py
@@ -307,6 +307,8 @@ class SineTransform(BijectiveTransform):
     """
     Sine transformation
 
+    The original parameter is expected to be in [-pi/2, pi/2]
+
     Parameters
     ----------
     name_mapping : tuple[list[str], list[str]]
@@ -334,6 +336,8 @@ class CosineTransform(BijectiveTransform):
     """
     Cosine transformation
 
+    The original parameter is expected to be in [0, pi]
+
     Parameters
     ----------
     name_mapping : tuple[list[str], list[str]]