diff --git a/src/libcinnabar.rs b/src/libcinnabar.rs
index 43e630ed3..ef519768a 100644
--- a/src/libcinnabar.rs
+++ b/src/libcinnabar.rs
@@ -171,11 +171,11 @@ unsafe fn ensure_notes(t: *mut cinnabar_notes_tree) {
         let oid;
         let mut flags = 0;
         if ptr::eq(t, &git2hg.0) {
-            oid = GIT2HG_OID.clone();
+            oid = GIT2HG_OID;
         } else if ptr::eq(t, &hg2git.0) {
-            oid = HG2GIT_OID.clone();
+            oid = HG2GIT_OID;
         } else if ptr::eq(t, &files_meta.0) {
-            oid = FILES_META_OID.clone();
+            oid = FILES_META_OID;
             if METADATA_FLAGS & FILES_META == 0 {
                 flags = NOTES_INIT_EMPTY;
             }
@@ -260,7 +260,7 @@ pub unsafe extern "C" fn add_files_meta(
 
 pub unsafe fn store_metadata_notes(
     notes: *mut cinnabar_notes_tree,
-    reference: *const object_id,
+    reference: CommitId,
 ) -> CommitId {
     let mut result = object_id::default();
     let mut tree = object_id::default();
@@ -274,7 +274,7 @@ pub unsafe fn store_metadata_notes(
     }
     let mut tree = TreeId::from_unchecked(GitObjectId::from(tree));
     if tree.is_null() {
-        result = reference.as_ref().unwrap().clone();
+        result = reference.into();
         if GitObjectId::from(result.clone()).is_null() {
             tree = RawTree::EMPTY_OID;
         }
diff --git a/src/libgit.rs b/src/libgit.rs
index 35b8df791..f4981c8a1 100644
--- a/src/libgit.rs
+++ b/src/libgit.rs
@@ -62,12 +62,12 @@ impl From<object_id> for GitObjectId {
     }
 }
 
-pub static mut METADATA_OID: object_id = object_id([0; GIT_MAX_RAWSZ], GIT_HASH_SHA1);
-pub static mut CHANGESETS_OID: object_id = object_id([0; GIT_MAX_RAWSZ], GIT_HASH_SHA1);
-pub static mut MANIFESTS_OID: object_id = object_id([0; GIT_MAX_RAWSZ], GIT_HASH_SHA1);
-pub static mut GIT2HG_OID: object_id = object_id([0; GIT_MAX_RAWSZ], GIT_HASH_SHA1);
-pub static mut HG2GIT_OID: object_id = object_id([0; GIT_MAX_RAWSZ], GIT_HASH_SHA1);
-pub static mut FILES_META_OID: object_id = object_id([0; GIT_MAX_RAWSZ], GIT_HASH_SHA1);
+pub static mut METADATA_OID: CommitId = CommitId::NULL;
+pub static mut CHANGESETS_OID: CommitId = CommitId::NULL;
+pub static mut MANIFESTS_OID: CommitId = CommitId::NULL;
+pub static mut GIT2HG_OID: CommitId = CommitId::NULL;
+pub static mut HG2GIT_OID: CommitId = CommitId::NULL;
+pub static mut FILES_META_OID: CommitId = CommitId::NULL;
 
 #[allow(non_camel_case_types)]
 #[repr(C)]
diff --git a/src/main.rs b/src/main.rs
index 59fdefb5b..98cbffd41 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -941,9 +941,9 @@ fn do_reclone(rebase: bool) -> Result<(), String> {
         }
     }
 
-    let old_changesets_oid = GitObjectId::from(unsafe { libgit::CHANGESETS_OID.clone() });
+    let old_changesets_oid = unsafe { libgit::CHANGESETS_OID };
     let mut old_git2hg = {
-        let git2hg_oid = GitObjectId::from(unsafe { libgit::GIT2HG_OID.clone() });
+        let git2hg_oid = unsafe { libgit::GIT2HG_OID };
         if git2hg_oid.is_null() {
             None
         } else {
@@ -953,9 +953,9 @@ fn do_reclone(rebase: bool) -> Result<(), String> {
     };
 
     let current_metadata_oid = unsafe {
-        let current_metadata_oid = METADATA_OID.clone();
+        let current_metadata_oid = METADATA_OID;
         do_reload(&object_id::default());
-        METADATA_OID = current_metadata_oid.clone();
+        METADATA_OID = current_metadata_oid;
         current_metadata_oid
     };
 
@@ -1078,7 +1078,6 @@ fn do_reclone(rebase: bool) -> Result<(), String> {
     .and_then(|()| {
         // If all the changesets we had in store weren't pulled from the remotes
         // above, try fetching them from skip-default-update remotes.
-        let old_changesets_oid = CommitId::from_unchecked(old_changesets_oid);
         if old_changesets_oid.is_null() {
             return Ok(());
         }
@@ -2330,7 +2329,7 @@ fn do_fsck(force: bool, full: bool, commits: Vec<OsString>) -> Result<i32, Strin
         );
         return Ok(1);
     }
-    let metadata_cid = unsafe { CommitId::from_unchecked(GitObjectId::from(METADATA_OID.clone())) };
+    let metadata_cid = unsafe { METADATA_OID };
     let checked_cid = if force {
         None
     } else {
diff --git a/src/store.rs b/src/store.rs
index 608032408..eafc30d48 100644
--- a/src/store.rs
+++ b/src/store.rs
@@ -1560,9 +1560,7 @@ pub fn do_check_files() -> bool {
         transaction
             .update(
                 BROKEN_REF,
-                unsafe {
-                    CommitId::from_unchecked(GitObjectId::from(crate::libgit::METADATA_OID.clone()))
-                },
+                unsafe { crate::libgit::METADATA_OID },
                 None,
                 "post-pull check",
             )
@@ -2070,12 +2068,12 @@ pub unsafe extern "C" fn init_metadata(c: *const commit) {
     let cid = if let Some(c) = c.as_ref() {
         CommitId::from_unchecked(GitObjectId::from(commit_oid(c).as_ref().unwrap().clone()))
     } else {
-        METADATA_OID = object_id::default();
-        CHANGESETS_OID = object_id::default();
-        MANIFESTS_OID = object_id::default();
-        HG2GIT_OID = object_id::default();
-        GIT2HG_OID = object_id::default();
-        FILES_META_OID = object_id::default();
+        METADATA_OID = CommitId::NULL;
+        CHANGESETS_OID = CommitId::NULL;
+        MANIFESTS_OID = CommitId::NULL;
+        HG2GIT_OID = CommitId::NULL;
+        GIT2HG_OID = CommitId::NULL;
+        FILES_META_OID = CommitId::NULL;
         return;
     };
     let c = RawCommit::read(cid).unwrap();
@@ -2091,7 +2089,7 @@ pub unsafe extern "C" fn init_metadata(c: *const commit) {
         &mut GIT2HG_OID,
         &mut FILES_META_OID,
     ]) {
-        *field = (*cid).into();
+        *field = *cid;
     }
     for flag in c.body().split(|&b| b == b' ') {
         match flag {
@@ -2177,15 +2175,13 @@ pub fn do_store_metadata() -> CommitId {
     let mut tree = object_id::default();
     let mut previous = None;
     unsafe {
-        hg2git_ = store_metadata_notes(&mut *hg2git, &HG2GIT_OID);
-        git2hg_ = store_metadata_notes(&mut *git2hg, &GIT2HG_OID);
-        files_meta_ = store_metadata_notes(&mut *files_meta, &FILES_META_OID);
+        hg2git_ = store_metadata_notes(&mut *hg2git, HG2GIT_OID);
+        git2hg_ = store_metadata_notes(&mut *git2hg, GIT2HG_OID);
+        files_meta_ = store_metadata_notes(&mut *files_meta, FILES_META_OID);
         manifests = store_manifests_metadata();
         changesets = store_changesets_metadata();
-        if !GitObjectId::from(METADATA_OID.clone()).is_null() {
-            previous = Some(CommitId::from_unchecked(GitObjectId::from(
-                METADATA_OID.clone(),
-            )));
+        if !METADATA_OID.is_null() {
+            previous = Some(METADATA_OID);
         }
         store_replace_map(&mut tree);
     }