diff --git a/eppo_core/src/configuration_store.rs b/eppo_core/src/configuration_store.rs
index 260acd04..3272b55f 100644
--- a/eppo_core/src/configuration_store.rs
+++ b/eppo_core/src/configuration_store.rs
@@ -67,7 +67,7 @@ mod tests {
             let _ = std::thread::spawn(move || {
                 store.set_configuration(Arc::new(Configuration::from_server_response(
                     UniversalFlagConfig {
-                        wire_json: Vec::from(b"test-bytes"),
+                        wire_json: b"test-bytes".to_vec(),
                         compiled: CompiledFlagsConfig {
                             created_at: Utc::now(),
                             environment: Environment {
diff --git a/eppo_core/src/context_attributes.rs b/eppo_core/src/context_attributes.rs
index f7005675..53ef2313 100644
--- a/eppo_core/src/context_attributes.rs
+++ b/eppo_core/src/context_attributes.rs
@@ -50,8 +50,10 @@ where
                         // We can go a step further and remove `AttributeValue::Boolean` altogether
                         // (from `eppo_core`), forcing it to be converted to a string before any
                         // evaluation.
-                        acc.categorical
-                            .insert(key.to_owned(), value.to_string().into());
+                        acc.categorical.insert(
+                            key.to_owned(),
+                            Str::from_static_str(if value { "true" } else { "false" }),
+                        );
                     }
                     AttributeValue::Null => {
                         // Nulls are missing values and are ignored.
diff --git a/eppo_core/src/lib.rs b/eppo_core/src/lib.rs
index 8e72352b..fe1d770a 100644
--- a/eppo_core/src/lib.rs
+++ b/eppo_core/src/lib.rs
@@ -67,9 +67,9 @@ mod error;
 mod sdk_metadata;
 mod str;
 
+pub use crate::str::Str;
 pub use attributes::{AttributeValue, Attributes};
 pub use configuration::Configuration;
 pub use context_attributes::ContextAttributes;
 pub use error::{Error, EvaluationError, Result};
 pub use sdk_metadata::SdkMetadata;
-pub use str::Str;