diff --git a/Cargo.lock b/Cargo.lock
index 981fc718..62074006 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -320,6 +320,7 @@ dependencies = [
  "digest 0.10.7",
  "hex-literal",
  "sha1 0.10.6",
+ "zeroize",
 ]
 
 [[package]]
diff --git a/sha1-checked/Cargo.toml b/sha1-checked/Cargo.toml
index d8dd97f2..afd9bae9 100644
--- a/sha1-checked/Cargo.toml
+++ b/sha1-checked/Cargo.toml
@@ -20,6 +20,7 @@ exclude = [
 [dependencies]
 digest = "0.10.7"
 sha1 = { version = "0.10.6", default-features = false, features = ["compress"] }
+zeroize = { version = "1.7", default-features = false, optional = true }
 
 [dev-dependencies]
 digest = { version = "0.10.7", features = ["dev"] }
@@ -29,7 +30,7 @@ hex-literal = "0.4"
 default = ["oid", "std"]
 std = ["digest/std", "sha1/std"]
 oid = ["digest/oid", "sha1/oid"] # Enable OID support
-zeroize = []
+zeroize = ["dep:zeroize"]
 
 
 [package.metadata.docs.rs]
diff --git a/sha1-checked/src/lib.rs b/sha1-checked/src/lib.rs
index 39e11965..1dcf28da 100644
--- a/sha1-checked/src/lib.rs
+++ b/sha1-checked/src/lib.rs
@@ -26,14 +26,14 @@ use core::slice::from_ref;
 #[cfg(feature = "std")]
 extern crate std;
 
-#[cfg(feature = "zeroize")]
-use digest::zeroize::{Zeroize, ZeroizeOnDrop};
 use digest::{
     block_buffer::{BlockBuffer, Eager},
     core_api::BlockSizeUser,
     typenum::{Unsigned, U20, U64},
     FixedOutput, FixedOutputReset, HashMarker, Output, OutputSizeUser, Reset, Update,
 };
+#[cfg(feature = "zeroize")]
+use zeroize::{Zeroize, ZeroizeOnDrop};
 
 const BLOCK_SIZE: usize = <sha1::Sha1Core as BlockSizeUser>::BlockSize::USIZE;
 const STATE_LEN: usize = 5;
@@ -212,16 +212,6 @@ impl FixedOutputReset for Sha1 {
     }
 }
 
-impl Drop for Sha1 {
-    #[inline]
-    fn drop(&mut self) {
-        #[cfg(feature = "zeroize")]
-        {
-            self.buffer.zeroize();
-        }
-    }
-}
-
 #[cfg(feature = "zeroize")]
 impl ZeroizeOnDrop for Sha1 {}