diff --git a/CHANGELOG.md b/CHANGELOG.md
index c6a739134..baa71f471 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -34,6 +34,7 @@
 * nostr: update `PartialEvent` methods ([Yuki Kishimoto])
 * nostr: change `EventBuilder::award_badge` fingerprint ([Yuki Kishimoto])
 * nostr: add NIP-50 support to `Filter::match_event` method ([Yuki Kishimoto])
+* nostr: remove `Arc<T>` from `OnceCell<T>` in `Event` and `Tag` ([Yuki Kishimoto])
 * pool: take mutex ownership instead of clone in `InternalRelayPool::get_events_from` ([Yuki Kishimoto])
 * pool: remove IDs collection from `InternalRelayPool::get_events_from` ([Yuki Kishimoto])
 * pool: better checks before perform queries or send messages to relays ([Yuki Kishimoto])
diff --git a/crates/nostr/src/event/mod.rs b/crates/nostr/src/event/mod.rs
index f4ced59ca..cec44f980 100644
--- a/crates/nostr/src/event/mod.rs
+++ b/crates/nostr/src/event/mod.rs
@@ -7,8 +7,6 @@
 
 use alloc::collections::{BTreeMap, BTreeSet};
 use alloc::string::{String, ToString};
-#[cfg(feature = "std")]
-use alloc::sync::Arc;
 use alloc::vec::Vec;
 use core::cmp::Ordering;
 use core::fmt;
@@ -137,7 +135,7 @@ pub struct Event {
     deser_order: Vec<EventKey>,
     /// Tags indexes
     #[cfg(feature = "std")]
-    tags_indexes: Arc<OnceCell<TagsIndexes>>,
+    tags_indexes: OnceCell<TagsIndexes>,
 }
 
 impl fmt::Debug for Event {
@@ -215,7 +213,7 @@ impl Event {
             },
             deser_order: Vec::new(),
             #[cfg(feature = "std")]
-            tags_indexes: Arc::new(OnceCell::new()),
+            tags_indexes: OnceCell::new(),
         }
     }
 
@@ -653,7 +651,7 @@ impl<'de> Deserialize<'de> for Event {
             inner: serde_json::from_value(value).map_err(serde::de::Error::custom)?,
             deser_order,
             #[cfg(feature = "std")]
-            tags_indexes: Arc::new(OnceCell::new()),
+            tags_indexes: OnceCell::new(),
         })
     }
 }
diff --git a/crates/nostr/src/event/tag/mod.rs b/crates/nostr/src/event/tag/mod.rs
index ff78a1c19..bc7c2c2eb 100644
--- a/crates/nostr/src/event/tag/mod.rs
+++ b/crates/nostr/src/event/tag/mod.rs
@@ -5,7 +5,6 @@
 //! Tag
 
 use alloc::string::{String, ToString};
-use alloc::sync::Arc;
 use alloc::vec::Vec;
 use core::cmp::Ordering;
 use core::hash::{Hash, Hasher};
@@ -37,7 +36,7 @@ use crate::{ImageDimensions, PublicKey, SingleLetterTag, Timestamp, UncheckedUrl
 #[derive(Debug, Clone)]
 pub struct Tag {
     buf: Vec<String>,
-    standardized: Arc<OnceCell<Option<TagStandard>>>,
+    standardized: OnceCell<Option<TagStandard>>,
 }
 
 impl PartialEq for Tag {
@@ -71,7 +70,7 @@ impl Tag {
     fn new(buf: Vec<String>, standardized: Option<TagStandard>) -> Self {
         Self {
             buf,
-            standardized: Arc::new(OnceCell::from(standardized)),
+            standardized: OnceCell::from(standardized),
         }
     }
 
@@ -79,7 +78,7 @@ impl Tag {
     fn new_with_empty_cell(buf: Vec<String>) -> Self {
         Self {
             buf,
-            standardized: Arc::new(OnceCell::new()),
+            standardized: OnceCell::new(),
         }
     }
 
@@ -146,10 +145,7 @@ impl Tag {
 
     /// Consume tag and get standardized tag
     pub fn to_standardized(self) -> Option<TagStandard> {
-        // TODO: replace with `Arc::unwrap_or_clone(self.standardized)` when MSRV will be >= 1.76.0
-        let standardized: OnceCell<Option<TagStandard>> =
-            Arc::try_unwrap(self.standardized).unwrap_or_else(|arc| (*arc).clone());
-        match standardized.into_inner() {
+        match self.standardized.into_inner() {
             Some(inner) => inner,
             None => TagStandard::parse(&self.buf).ok(),
         }