diff --git a/crates/stackable-operator/CHANGELOG.md b/crates/stackable-operator/CHANGELOG.md
index 83e9d218a..ce8e1be1e 100644
--- a/crates/stackable-operator/CHANGELOG.md
+++ b/crates/stackable-operator/CHANGELOG.md
@@ -8,6 +8,11 @@ All notable changes to this project will be documented in this file.
 
 - Implement `PartialEq` for most _Snafu_ Error enums ([#757]).
 
+## Fixed
+
+- Fix wrong schema (and thus CRD) for `config.affinity.nodeSelector` ([#752]).
+
+[#752]: https://github.com/stackabletech/operator-rs/pull/752
 [#757]: https://github.com/stackabletech/operator-rs/pull/757
 
 ## [0.65.0] - 2024-03-25
diff --git a/crates/stackable-operator/src/commons/affinity.rs b/crates/stackable-operator/src/commons/affinity.rs
index 6bbaf8ff0..7973f9daa 100644
--- a/crates/stackable-operator/src/commons/affinity.rs
+++ b/crates/stackable-operator/src/commons/affinity.rs
@@ -42,8 +42,18 @@ pub struct StackableAffinity {
     pub node_selector: Option<StackableNodeSelector>,
 }
 
+// We can not simply use [`BTreeMap<String, String>`] in [`StackableAffinity`], as the fields need to be [`Atomic`].
+// We can not mark it as [`Atomic`], as [`crate::config::fragment::FromFragment`] is already implemented for
+// [`BTreeMap<String, String>`].
+//
+// We `#[serde(flatten)]` the contained [`BTreeMap<String, String>`], so `serde_yaml` can deserialize everything as
+// expected.
+// FIXME: The generated JsonSchema will be wrong, so until https://github.com/GREsau/schemars/issues/259 is fixed, we
+// need to use `#[schemars(deny_unknown_fields)]`.
+// See https://github.com/stackabletech/operator-rs/pull/752#issuecomment-2017630433 for details.
 #[derive(Clone, Debug, Eq, Deserialize, JsonSchema, PartialEq, Serialize)]
 #[serde(rename_all = "camelCase")]
+#[schemars(deny_unknown_fields)]
 pub struct StackableNodeSelector {
     #[serde(flatten)]
     pub node_selector: BTreeMap<String, String>,