diff --git a/Cargo.toml b/Cargo.toml
index c72197d7..72e3ccf0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -41,7 +41,6 @@ encoding_rs = "0.8.13"
 lazycell = "1.3.0"
 lazy_static = "1.3.0"
 memchr = "2.1.2"
-safemem = "0.3.3"
 selectors = "0.22.0"
 thiserror = "1.0.2"
 hashbrown = "0.13.1"
diff --git a/src/memory/arena.rs b/src/memory/arena.rs
index 8e3e2b5f..1cb32f2f 100644
--- a/src/memory/arena.rs
+++ b/src/memory/arena.rs
@@ -1,5 +1,4 @@
 use super::{MemoryLimitExceededError, SharedMemoryLimiter};
-use safemem::copy_over;
 
 /// Preallocated region of memory that can grow and never deallocates during the lifetime of
 /// the limiter.
@@ -48,10 +47,8 @@ impl Arena {
     }
 
     pub fn shift(&mut self, byte_count: usize) {
-        let remainder_len = self.data.len() - byte_count;
-
-        copy_over(&mut self.data, byte_count, 0, remainder_len);
-        self.data.truncate(remainder_len);
+        self.data.copy_within(byte_count.., 0);
+        self.data.truncate(self.data.len() - byte_count);
     }
 
     pub fn bytes(&self) -> &[u8] {