diff --git a/eden/mononoke/edenapi_service/src/handlers/commit.rs b/eden/mononoke/edenapi_service/src/handlers/commit.rs
index 175f9abbb6..6951a1943e 100644
--- a/eden/mononoke/edenapi_service/src/handlers/commit.rs
+++ b/eden/mononoke/edenapi_service/src/handlers/commit.rs
@@ -24,7 +24,9 @@ use types::HgId;
 use crate::context::ServerContext;
 use crate::errors::ErrorKind;
 use crate::middleware::RequestContext;
-use crate::utils::{cbor_stream, get_repo, parse_cbor_request, parse_wire_request};
+use crate::utils::{
+    cbor_stream, get_repo, parse_cbor_request, parse_wire_request, simple_cbor_stream,
+};
 
 use super::{EdenApiMethod, HandlerInfo};
 
@@ -76,18 +78,21 @@ pub async fn hash_to_location(state: &mut State) -> Result<impl TryIntoResponse,
         hg_repo_ctx: HgRepoContext,
         master_heads: Vec<HgChangesetId>,
         hg_cs_ids: Vec<HgChangesetId>,
-    ) -> Result<impl Stream<Item = Result<CommitHashToLocationResponse, Error>>, Error> {
+    ) -> impl Stream<Item = CommitHashToLocationResponse> {
         let hgcsid_to_location = hg_repo_ctx
             .many_changeset_ids_to_locations(master_heads, hg_cs_ids.clone())
-            .await?;
-        let responses = hgcsid_to_location.into_iter().map(|(hgcsid, location)| {
-            let response = CommitHashToLocationResponse {
+            .await;
+        let responses = hg_cs_ids.into_iter().map(move |hgcsid| {
+            let result = hgcsid_to_location
+                .as_ref()
+                .map(|hsh| hsh.get(&hgcsid).map(|l| l.map_descendant(|x| x.into())))
+                .map_err(|e| (&*e).into());
+            CommitHashToLocationResponse {
                 hgid: hgcsid.into(),
-                location: location.map_descendant(|x| x.into()),
-            };
-            Ok(response)
+                result,
+            }
         });
-        Ok(stream::iter(responses))
+        stream::iter(responses)
     }
 
     let params = HashToLocationParams::take_from(state);
@@ -103,6 +108,7 @@ pub async fn hash_to_location(state: &mut State) -> Result<impl TryIntoResponse,
     let hg_repo_ctx = get_repo(&sctx, &rctx, &params.repo, None).await?;
 
     let batch = parse_wire_request::<WireCommitHashToLocationRequestBatch>(state).await?;
+    let unfiltered = batch.unfiltered;
     let master_heads = batch
         .master_heads
         .into_iter()
@@ -117,9 +123,22 @@ pub async fn hash_to_location(state: &mut State) -> Result<impl TryIntoResponse,
             move |chunk| hash_to_location_chunk(ctx.clone(), master_heads.clone(), chunk)
         })
         .buffer_unordered(3)
-        .try_flatten()
-        .map_ok(|response| response.to_wire());
-    Ok(cbor_stream(rctx, response))
+        .flatten()
+        .filter(move |v| {
+            // The old behavior is to filter out error and None results. We want to preserve that
+            // behavior for old clients since they will not be able to deserialize other results.
+            let to_keep = if unfiltered == Some(true) {
+                true
+            } else {
+                match v.result {
+                    Ok(Some(_)) => true,
+                    _ => false,
+                }
+            };
+            futures::future::ready(to_keep)
+        })
+        .map(|response| response.to_wire());
+    Ok(simple_cbor_stream(rctx, response))
 }
 
 pub async fn revlog_data(state: &mut State) -> Result<impl TryIntoResponse, HttpError> {
diff --git a/eden/mononoke/edenapi_service/src/utils/cbor.rs b/eden/mononoke/edenapi_service/src/utils/cbor.rs
index 4cf2ccbd0f..c89e31601b 100644
--- a/eden/mononoke/edenapi_service/src/utils/cbor.rs
+++ b/eden/mononoke/edenapi_service/src/utils/cbor.rs
@@ -55,6 +55,17 @@ where
     StreamBody::new(content_stream, cbor_mime())
 }
 
+pub fn simple_cbor_stream<S, T>(rctx: RequestContext, stream: S) -> impl TryIntoResponse
+where
+    S: Stream<Item = T> + Send + 'static,
+    T: Serialize + Send + 'static,
+{
+    let byte_stream = stream.then(|item| async { to_cbor_bytes(item) });
+    let content_stream = ContentStream::new(byte_stream).forward_err(rctx.error_tx);
+
+    StreamBody::new(content_stream, cbor_mime())
+}
+
 pub async fn parse_cbor_request<R: DeserializeOwned>(state: &mut State) -> Result<R, HttpError> {
     let body = get_request_body(state).await?;
     serde_cbor::from_slice(&body)
diff --git a/eden/mononoke/edenapi_service/src/utils/mod.rs b/eden/mononoke/edenapi_service/src/utils/mod.rs
index 094e16d521..af63823fd6 100644
--- a/eden/mononoke/edenapi_service/src/utils/mod.rs
+++ b/eden/mononoke/edenapi_service/src/utils/mod.rs
@@ -22,7 +22,10 @@ use crate::middleware::RequestContext;
 pub mod cbor;
 pub mod convert;
 
-pub use cbor::{cbor_mime, cbor_stream, parse_cbor_request, parse_wire_request, to_cbor_bytes};
+pub use cbor::{
+    cbor_mime, cbor_stream, parse_cbor_request, parse_wire_request, simple_cbor_stream,
+    to_cbor_bytes,
+};
 pub use convert::{to_hg_path, to_mononoke_path, to_mpath};
 
 pub async fn get_repo(
diff --git a/eden/mononoke/tests/integration/test-edenapi-server-commit-hash-to-location.t b/eden/mononoke/tests/integration/test-edenapi-server-commit-hash-to-location.t
index 958b5764fa..11fbd73d01 100644
--- a/eden/mononoke/tests/integration/test-edenapi-server-commit-hash-to-location.t
+++ b/eden/mononoke/tests/integration/test-edenapi-server-commit-hash-to-location.t
@@ -51,6 +51,7 @@ Populate test repo
   o  426bada5c67598ca65036d57d9e4b64b0c1ce7a0 A
   
 
+
 Blobimport test repo.
   $ cd ..
   $ blobimport repo-hg/.hg repo
@@ -61,6 +62,70 @@ Start up EdenAPI server.
   $ wait_for_mononoke
 
 Create and send file data request.
+  $ edenapi_make_req commit-hash-to-location > req.cbor <<EOF
+  > {
+  >   "master_heads": [
+  >     "$G"
+  >   ],
+  >   "hgids": [
+  >     "$F",
+  >     "$D",
+  >     "$C",
+  >     "$B",
+  >     "$A",
+  >     "$F",
+  >     "$H",
+  >     "000000000000000000000000000000123456789a"
+  >   ],
+  >   "unfiltered": true
+  > }
+  > EOF
+  Reading from stdin
+  Generated request: WireCommitHashToLocationRequestBatch {
+      client_head: Some(
+          WireHgId("1b794c59b583e47686701d0142848e90a3a94a7d"),
+      ),
+      hgids: [
+          WireHgId("bb56d4161ee371c720dbc8b504810c62a22fe314"),
+          WireHgId("f585351a92f85104bff7c284233c338b10eb1df7"),
+          WireHgId("26805aba1e600a82e93661149f2313866a221a7b"),
+          WireHgId("112478962961147124edd43549aedd1a335e44bf"),
+          WireHgId("426bada5c67598ca65036d57d9e4b64b0c1ce7a0"),
+          WireHgId("bb56d4161ee371c720dbc8b504810c62a22fe314"),
+          WireHgId("06383dd46c9bcbca9300252b4b6cddad88f8af21"),
+          WireHgId("000000000000000000000000000000123456789a"),
+      ],
+      master_heads: [
+          WireHgId("1b794c59b583e47686701d0142848e90a3a94a7d"),
+      ],
+      unfiltered: Some(
+          true,
+      ),
+  }
+
+  $ sslcurl -s "https://localhost:$MONONOKE_SOCKET/edenapi/repo/commit/hash_to_location" --data-binary @req.cbor > res.cbor
+
+Check files in response.
+  $ edenapi_read_res commit-hash-to-location res.cbor
+  Reading from file: "res.cbor"
+  000000000000000000000000000000123456789a =>
+      Ok(None)
+  06383dd46c9bcbca9300252b4b6cddad88f8af21 =>
+      Ok(None)
+  112478962961147124edd43549aedd1a335e44bf =>
+      Ok(Some(Location(descendant=49cb92066bfd0763fff729c354345650b7428554, dist=1)))
+  26805aba1e600a82e93661149f2313866a221a7b =>
+      Ok(Some(Location(descendant=f585351a92f85104bff7c284233c338b10eb1df7, dist=1)))
+  426bada5c67598ca65036d57d9e4b64b0c1ce7a0 =>
+      Ok(Some(Location(descendant=49cb92066bfd0763fff729c354345650b7428554, dist=2)))
+  bb56d4161ee371c720dbc8b504810c62a22fe314 =>
+      Ok(Some(Location(descendant=1b794c59b583e47686701d0142848e90a3a94a7d, dist=1)))
+  bb56d4161ee371c720dbc8b504810c62a22fe314 =>
+      Ok(Some(Location(descendant=1b794c59b583e47686701d0142848e90a3a94a7d, dist=1)))
+  f585351a92f85104bff7c284233c338b10eb1df7 =>
+      Ok(Some(Location(descendant=f585351a92f85104bff7c284233c338b10eb1df7, dist=0)))
+
+And now again but this time with the default value for unfiltered
   $ edenapi_make_req commit-hash-to-location > req.cbor <<EOF
   > {
   >   "master_heads": [
@@ -96,6 +161,7 @@ Create and send file data request.
       master_heads: [
           WireHgId("1b794c59b583e47686701d0142848e90a3a94a7d"),
       ],
+      unfiltered: None,
   }
 
   $ sslcurl -s "https://localhost:$MONONOKE_SOCKET/edenapi/repo/commit/hash_to_location" --data-binary @req.cbor > res.cbor
@@ -104,12 +170,14 @@ Check files in response.
   $ edenapi_read_res commit-hash-to-location res.cbor
   Reading from file: "res.cbor"
   112478962961147124edd43549aedd1a335e44bf =>
-      Location(descendant=49cb92066bfd0763fff729c354345650b7428554, dist=1)
+      Ok(Some(Location(descendant=49cb92066bfd0763fff729c354345650b7428554, dist=1)))
   26805aba1e600a82e93661149f2313866a221a7b =>
-      Location(descendant=f585351a92f85104bff7c284233c338b10eb1df7, dist=1)
+      Ok(Some(Location(descendant=f585351a92f85104bff7c284233c338b10eb1df7, dist=1)))
   426bada5c67598ca65036d57d9e4b64b0c1ce7a0 =>
-      Location(descendant=49cb92066bfd0763fff729c354345650b7428554, dist=2)
+      Ok(Some(Location(descendant=49cb92066bfd0763fff729c354345650b7428554, dist=2)))
   bb56d4161ee371c720dbc8b504810c62a22fe314 =>
-      Location(descendant=1b794c59b583e47686701d0142848e90a3a94a7d, dist=1)
+      Ok(Some(Location(descendant=1b794c59b583e47686701d0142848e90a3a94a7d, dist=1)))
+  bb56d4161ee371c720dbc8b504810c62a22fe314 =>
+      Ok(Some(Location(descendant=1b794c59b583e47686701d0142848e90a3a94a7d, dist=1)))
   f585351a92f85104bff7c284233c338b10eb1df7 =>
-      Location(descendant=f585351a92f85104bff7c284233c338b10eb1df7, dist=0)
+      Ok(Some(Location(descendant=f585351a92f85104bff7c284233c338b10eb1df7, dist=0)))
diff --git a/eden/mononoke/tests/integration/test-edenapi-server-segmented-changelog-setup.t b/eden/mononoke/tests/integration/test-edenapi-server-segmented-changelog-setup.t
index 2d0059c140..c31855b21e 100644
--- a/eden/mononoke/tests/integration/test-edenapi-server-segmented-changelog-setup.t
+++ b/eden/mononoke/tests/integration/test-edenapi-server-segmented-changelog-setup.t
@@ -104,6 +104,7 @@ Create and send file data request.
       master_heads: [
           WireHgId("1b794c59b583e47686701d0142848e90a3a94a7d"),
       ],
+      unfiltered: None,
   }
 
   $ sslcurl -s "https://localhost:$MONONOKE_SOCKET/edenapi/repo/commit/hash_to_location" --data-binary @req.cbor > res.cbor
@@ -112,12 +113,14 @@ Check files in response.
   $ edenapi_read_res commit-hash-to-location res.cbor
   Reading from file: "res.cbor"
   112478962961147124edd43549aedd1a335e44bf =>
-      Location(descendant=49cb92066bfd0763fff729c354345650b7428554, dist=1)
+      Ok(Some(Location(descendant=49cb92066bfd0763fff729c354345650b7428554, dist=1)))
   26805aba1e600a82e93661149f2313866a221a7b =>
-      Location(descendant=f585351a92f85104bff7c284233c338b10eb1df7, dist=1)
+      Ok(Some(Location(descendant=f585351a92f85104bff7c284233c338b10eb1df7, dist=1)))
   426bada5c67598ca65036d57d9e4b64b0c1ce7a0 =>
-      Location(descendant=49cb92066bfd0763fff729c354345650b7428554, dist=2)
+      Ok(Some(Location(descendant=49cb92066bfd0763fff729c354345650b7428554, dist=2)))
   bb56d4161ee371c720dbc8b504810c62a22fe314 =>
-      Location(descendant=1b794c59b583e47686701d0142848e90a3a94a7d, dist=1)
+      Ok(Some(Location(descendant=1b794c59b583e47686701d0142848e90a3a94a7d, dist=1)))
+  bb56d4161ee371c720dbc8b504810c62a22fe314 =>
+      Ok(Some(Location(descendant=1b794c59b583e47686701d0142848e90a3a94a7d, dist=1)))
   f585351a92f85104bff7c284233c338b10eb1df7 =>
-      Location(descendant=f585351a92f85104bff7c284233c338b10eb1df7, dist=0)
+      Ok(Some(Location(descendant=f585351a92f85104bff7c284233c338b10eb1df7, dist=0)))
diff --git a/eden/scm/lib/edenapi/src/client.rs b/eden/scm/lib/edenapi/src/client.rs
index 8d7f1d8862..2a2829909c 100644
--- a/eden/scm/lib/edenapi/src/client.rs
+++ b/eden/scm/lib/edenapi/src/client.rs
@@ -570,6 +570,7 @@ impl EdenApi for Client {
             let batch = CommitHashToLocationRequestBatch {
                 master_heads: master_heads.clone(),
                 hgids,
+                unfiltered: Some(true),
             };
             self.log_request(&batch, "commit_hash_to_location");
             batch.to_wire()
diff --git a/eden/scm/lib/edenapi/tools/read_res/src/main.rs b/eden/scm/lib/edenapi/tools/read_res/src/main.rs
index 6f1275838e..4459726f0f 100644
--- a/eden/scm/lib/edenapi/tools/read_res/src/main.rs
+++ b/eden/scm/lib/edenapi/tools/read_res/src/main.rs
@@ -442,14 +442,24 @@ fn cmd_commit_hash_to_location(args: CommitHashToLocationArgs) -> Result<()> {
     let mut response_list: Vec<WireCommitHashToLocationResponse> = read_input(args.input, None)?;
     response_list.sort_by_key(|r| r.hgid);
     let iter = response_list
-        .iter()
+        .into_iter()
         .skip(args.start.unwrap_or(0))
         .take(args.limit.unwrap_or(usize::MAX));
     for response in iter {
-        println!(
-            "{} =>\n    Location(descendant={}, dist={})",
-            response.hgid, response.location.descendant, response.location.distance
-        );
+        if let Some(result) = response.result {
+            let s = match result {
+                Ok(Some(l)) => format!(
+                    "Ok(Some(Location(descendant={}, dist={})))",
+                    l.descendant, l.distance
+                ),
+                Ok(None) => String::from("Ok(None)"),
+                Err(e) => format!(
+                    "Err({})",
+                    e.message.unwrap_or_else(|| String::from("error"))
+                ),
+            };
+            println!("{} =>\n    {}", response.hgid, s);
+        }
     }
     Ok(())
 }
diff --git a/eden/scm/lib/edenapi/types/src/commit.rs b/eden/scm/lib/edenapi/types/src/commit.rs
index bbfa85f6e4..629c298f02 100644
--- a/eden/scm/lib/edenapi/types/src/commit.rs
+++ b/eden/scm/lib/edenapi/types/src/commit.rs
@@ -5,6 +5,7 @@
  * GNU General Public License version 2.
  */
 
+use anyhow::Result;
 use bytes::Bytes;
 #[cfg(any(test, feature = "for-tests"))]
 use quickcheck::Arbitrary;
@@ -13,6 +14,8 @@ use serde_derive::{Deserialize, Serialize};
 use dag_types::Location;
 use types::hgid::HgId;
 
+use crate::ServerError;
+
 /// Given a graph location, return `count` hashes following first parent links.
 ///
 /// Example:
@@ -83,13 +86,14 @@ impl Arbitrary for CommitLocationToHashRequestBatch {
 pub struct CommitHashToLocationRequestBatch {
     pub master_heads: Vec<HgId>,
     pub hgids: Vec<HgId>,
+    pub unfiltered: Option<bool>,
 }
 
-#[derive(Clone, Debug, Default, Eq, Hash, Ord, PartialEq, PartialOrd)]
-#[derive(Serialize, Deserialize)]
+#[derive(Clone, Debug, Eq, PartialEq)]
+#[derive(Serialize)] // used to convert to Python
 pub struct CommitHashToLocationResponse {
     pub hgid: HgId,
-    pub location: Location<HgId>,
+    pub result: Result<Option<Location<HgId>>, ServerError>,
 }
 
 #[cfg(any(test, feature = "for-tests"))]
@@ -98,6 +102,7 @@ impl Arbitrary for CommitHashToLocationRequestBatch {
         CommitHashToLocationRequestBatch {
             master_heads: Arbitrary::arbitrary(g),
             hgids: Arbitrary::arbitrary(g),
+            unfiltered: Arbitrary::arbitrary(g),
         }
     }
 }
@@ -107,7 +112,7 @@ impl Arbitrary for CommitHashToLocationResponse {
     fn arbitrary<G: quickcheck::Gen>(g: &mut G) -> Self {
         CommitHashToLocationResponse {
             hgid: Arbitrary::arbitrary(g),
-            location: Arbitrary::arbitrary(g),
+            result: Arbitrary::arbitrary(g),
         }
     }
 }
diff --git a/eden/scm/lib/edenapi/types/src/json.rs b/eden/scm/lib/edenapi/types/src/json.rs
index 5444deb26b..e9f2982fa6 100644
--- a/eden/scm/lib/edenapi/types/src/json.rs
+++ b/eden/scm/lib/edenapi/types/src/json.rs
@@ -154,9 +154,11 @@ pub fn parse_commit_hash_to_location_req(json: &Value) -> Result<CommitHashToLoc
         .context("could not be parsed as HgId")?;
         hgids.push(hgid);
     }
+    let unfiltered = json.get("unfiltered").map(|v| v.as_bool()).flatten();
     Ok(CommitHashToLocationRequestBatch {
         master_heads,
         hgids,
+        unfiltered,
     })
 }
 /// Parse a `FileRequest` from JSON.
@@ -653,6 +655,7 @@ impl ToJson for CommitHashToLocationRequestBatch {
         json!({
             "master_heads": self.master_heads.to_json(),
             "hgids": self.hgids.to_json(),
+            "unfiltered": self.unfiltered,
         })
     }
 }
diff --git a/eden/scm/lib/edenapi/types/src/wire/commit.rs b/eden/scm/lib/edenapi/types/src/wire/commit.rs
index e5b71ca35b..c7641986f0 100644
--- a/eden/scm/lib/edenapi/types/src/wire/commit.rs
+++ b/eden/scm/lib/edenapi/types/src/wire/commit.rs
@@ -16,7 +16,7 @@ use crate::commit::{
     CommitHashToLocationRequestBatch, CommitHashToLocationResponse, CommitLocationToHashRequest,
     CommitLocationToHashRequestBatch, CommitLocationToHashResponse,
 };
-use crate::wire::{ToApi, ToWire, WireHgId, WireToApiConversionError};
+use crate::wire::{ToApi, ToWire, WireHgId, WireResult, WireToApiConversionError};
 
 #[derive(Clone, Debug, Serialize, Deserialize, Eq, PartialEq)]
 pub struct WireCommitLocation {
@@ -182,6 +182,8 @@ pub struct WireCommitHashToLocationRequestBatch {
     pub hgids: Vec<WireHgId>,
     #[serde(rename = "3", default)]
     pub master_heads: Vec<WireHgId>,
+    #[serde(rename = "4")]
+    pub unfiltered: Option<bool>,
 }
 
 #[derive(Clone, Debug, Serialize, Deserialize, Eq, PartialEq)]
@@ -189,7 +191,9 @@ pub struct WireCommitHashToLocationResponse {
     #[serde(rename = "1")]
     pub hgid: WireHgId,
     #[serde(rename = "2")]
-    pub location: WireCommitLocation,
+    pub location: Option<WireCommitLocation>,
+    #[serde(rename = "3")]
+    pub result: Option<WireResult<Option<WireCommitLocation>>>,
 }
 
 impl ToWire for CommitHashToLocationRequestBatch {
@@ -201,6 +205,7 @@ impl ToWire for CommitHashToLocationRequestBatch {
             client_head,
             hgids: self.hgids.to_wire(),
             master_heads: self.master_heads.to_wire(),
+            unfiltered: self.unfiltered,
         }
     }
 }
@@ -220,6 +225,7 @@ impl ToApi for WireCommitHashToLocationRequestBatch {
         let api = Self::Api {
             master_heads,
             hgids: self.hgids.to_api()?,
+            unfiltered: self.unfiltered,
         };
         Ok(api)
     }
@@ -236,9 +242,14 @@ impl ToWire for CommitHashToLocationResponse {
     type Wire = WireCommitHashToLocationResponse;
 
     fn to_wire(self) -> Self::Wire {
+        let location = match self.result {
+            Ok(Some(x)) => Some(x.to_wire()),
+            _ => None,
+        };
         Self::Wire {
             hgid: self.hgid.to_wire(),
-            location: self.location.to_wire(),
+            location,
+            result: Some(self.result.to_wire()),
         }
     }
 }
@@ -248,9 +259,16 @@ impl ToApi for WireCommitHashToLocationResponse {
     type Error = WireToApiConversionError;
 
     fn to_api(self) -> Result<Self::Api, Self::Error> {
+        let result = match self.result {
+            Some(x) => x.to_api()?,
+            None => match self.location {
+                None => Ok(None),
+                Some(l) => Ok(Some(l.to_api()?)),
+            },
+        };
         let api = Self::Api {
             hgid: self.hgid.to_api()?,
-            location: self.location.to_api()?,
+            result,
         };
         Ok(api)
     }
diff --git a/eden/scm/lib/hgcommits/src/hybrid.rs b/eden/scm/lib/hgcommits/src/hybrid.rs
index 8c29066bd4..c445796003 100644
--- a/eden/scm/lib/hgcommits/src/hybrid.rs
+++ b/eden/scm/lib/hgcommits/src/hybrid.rs
@@ -93,13 +93,15 @@ impl RemoteIdConvertProtocol for EdenApiProtocol {
         };
         while let Some(response) = response.entries.next().await {
             let response = response.map_err(to_dag_error)?;
-            let path = AncestorPath {
-                x: Vertex::copy_from(response.location.descendant.as_ref()),
-                n: response.location.distance,
-                batch_size: 1,
-            };
-            let name = Vertex::copy_from(response.hgid.as_ref());
-            pairs.push((path, vec![name]));
+            if let Some(location) = response.result.map_err(to_dag_error)? {
+                let path = AncestorPath {
+                    x: Vertex::copy_from(location.descendant.as_ref()),
+                    n: location.distance,
+                    batch_size: 1,
+                };
+                let name = Vertex::copy_from(response.hgid.as_ref());
+                pairs.push((path, vec![name]));
+            }
         }
         Ok(pairs)
     }