diff --git a/relay-server/src/services/buffer/envelope_buffer/mod.rs b/relay-server/src/services/buffer/envelope_buffer/mod.rs
index 969d9a3565..ebe30bc76f 100644
--- a/relay-server/src/services/buffer/envelope_buffer/mod.rs
+++ b/relay-server/src/services/buffer/envelope_buffer/mod.rs
@@ -5,7 +5,6 @@ use std::time::Instant;
 
 use relay_base_schema::project::ProjectKey;
 use relay_config::Config;
-use stack_key::StackKey;
 
 use crate::envelope::Envelope;
 use crate::services::buffer::envelope_stack::sqlite::SqliteEnvelopeStackError;
@@ -213,10 +212,13 @@ where
                 self.priority_queue.change_priority_by(stack_key, |stack| {
                     let mut found = false;
                     for (subkey, readiness) in [
-                        (stack_key.lesser(), &mut stack.readiness.0),
-                        (stack_key.greater(), &mut stack.readiness.1),
+                        (stack_key.own_key, &mut stack.readiness.own_project_ready),
+                        (
+                            stack_key.sampling_key,
+                            &mut stack.readiness.sampling_project_ready,
+                        ),
                     ] {
-                        if subkey == project {
+                        if subkey == *project {
                             found = true;
                             if *readiness != is_ready {
                                 changed = true;
@@ -261,46 +263,38 @@ where
                 .remove(&stack_key);
         }
         self.priority_queue.remove(&stack_key);
+
         relay_statsd::metric!(
             gauge(RelayGauges::BufferStackCount) = self.priority_queue.len() as u64
         );
     }
 }
 
-mod stack_key {
-    use super::*;
-    /// Sorted stack key.
-    ///
-    /// Contains a pair of project keys. The lower key is always the first
-    /// element in the pair, such that `(k1, k2)` and `(k2, k1)` map to the same
-    /// stack key.
-    #[derive(Clone, Copy, Debug, Hash, PartialEq, Eq, PartialOrd, Ord)]
-    pub struct StackKey(ProjectKey, ProjectKey);
-
-    impl StackKey {
-        pub fn from_envelope(envelope: &Envelope) -> Self {
-            let own_key = envelope.meta().public_key();
-            let sampling_key = envelope.sampling_key().unwrap_or(own_key);
-            Self::new(own_key, sampling_key)
-        }
-
-        pub fn lesser(&self) -> &ProjectKey {
-            &self.0
-        }
+#[derive(Clone, Copy, Debug, Hash, PartialEq, Eq, PartialOrd, Ord)]
+pub struct StackKey {
+    own_key: ProjectKey,
+    sampling_key: ProjectKey,
+}
 
-        pub fn greater(&self) -> &ProjectKey {
-            &self.1
-        }
+impl StackKey {
+    pub fn from_envelope(envelope: &Envelope) -> Self {
+        let own_key = envelope.meta().public_key();
+        let sampling_key = envelope.sampling_key().unwrap_or(own_key);
+        Self::new(own_key, sampling_key)
+    }
 
-        pub fn iter(&self) -> impl Iterator<Item = ProjectKey> {
-            std::iter::once(self.0).chain((self.0 != self.1).then_some(self.1))
-        }
+    pub fn iter(&self) -> impl Iterator<Item = ProjectKey> {
+        let Self {
+            own_key,
+            sampling_key,
+        } = self;
+        std::iter::once(*own_key).chain((own_key != sampling_key).then_some(*sampling_key))
+    }
 
-        fn new(mut key1: ProjectKey, mut key2: ProjectKey) -> Self {
-            if key2 < key1 {
-                std::mem::swap(&mut key1, &mut key2);
-            }
-            Self(key1, key2)
+    fn new(own_key: ProjectKey, sampling_key: ProjectKey) -> Self {
+        Self {
+            own_key,
+            sampling_key,
         }
     }
 }
@@ -374,15 +368,21 @@ impl Ord for Priority {
 }
 
 #[derive(Debug)]
-struct Readiness(bool, bool);
+struct Readiness {
+    own_project_ready: bool,
+    sampling_project_ready: bool,
+}
 
 impl Readiness {
     fn new() -> Self {
-        Self(false, false)
+        Self {
+            own_project_ready: false,
+            sampling_project_ready: false,
+        }
     }
 
     fn ready(&self) -> bool {
-        self.0 && self.1
+        self.own_project_ready && self.sampling_project_ready
     }
 }
 
@@ -594,4 +594,26 @@ mod tests {
 
         assert!(buffer.pop().await.unwrap().is_none());
     }
+
+    #[tokio::test]
+    async fn project_keys_distinct() {
+        let project_key1 = ProjectKey::parse("a94ae32be2584e0bbd7a4cbb95971fed").unwrap();
+        let project_key2 = ProjectKey::parse("a94ae32be2584e0bbd7a4cbb95971fef").unwrap();
+
+        let stack_key1 = StackKey::new(project_key1, project_key2);
+        let stack_key2 = StackKey::new(project_key2, project_key1);
+
+        assert_ne!(stack_key1, stack_key2);
+
+        let mut buffer = EnvelopeBuffer::<MemoryStackProvider>::new();
+        buffer
+            .push(new_envelope(project_key1, Some(project_key2)))
+            .await
+            .unwrap();
+        buffer
+            .push(new_envelope(project_key2, Some(project_key1)))
+            .await
+            .unwrap();
+        assert_eq!(buffer.priority_queue.len(), 2);
+    }
 }