diff --git a/spec/API_specification/array_object.md b/spec/API_specification/array_object.md
index a8eb39104..c5ea23491 100644
--- a/spec/API_specification/array_object.md
+++ b/spec/API_specification/array_object.md
@@ -153,6 +153,9 @@ an array object supporting the following in-place Python operators:
 - `<<=`. May be implemented via `__ilshift__`.
 - `>>=`. May be implemented via `__irshift__`.
 
+An in-place operation must not change the dtype or shape of the in-place array
+as a result of {ref}`type-promotion` or {ref}`broadcasting`.
+
 ```{note}
 
 In-place operators must be supported as discussed in {ref}`copyview-mutability`.
diff --git a/spec/API_specification/type_promotion.md b/spec/API_specification/type_promotion.md
index d9862db88..a0e66f18c 100644
--- a/spec/API_specification/type_promotion.md
+++ b/spec/API_specification/type_promotion.md
@@ -102,9 +102,9 @@ arrays must be supported for:
 - `array <op> scalar`
 - `scalar <op> array`
 
-where `<op>` is a built-in operator (see {ref}`operators` for operators
-supported by the array object) and `scalar` has a compatible type and value
-to the array dtype:
+where `<op>` is a built-in operator, including in-place operators (see
+{ref}`operators` for operators supported by the array object) and `scalar` has
+a compatible type and value to the array dtype:
 - Python `bool` for a `bool` array dtype,
 - a Python `int` within the [bounds](data-types) of the given dtype for integer array dtypes,
 - a Python `int` or `float` for floating-point array dtypes