diff --git a/cli/src/cli_util.rs b/cli/src/cli_util.rs
index a7f4910d9..89d3119af 100644
--- a/cli/src/cli_util.rs
+++ b/cli/src/cli_util.rs
@@ -59,6 +59,7 @@ use jj_lib::backend::TreeValue;
 use jj_lib::commit::Commit;
 use jj_lib::config::ConfigError;
 use jj_lib::config::ConfigNamePathBuf;
+use jj_lib::config::ConfigResultExt as _;
 use jj_lib::config::StackedConfig;
 use jj_lib::conflicts::ConflictMarkerStyle;
 use jj_lib::file_util;
@@ -110,7 +111,6 @@ use jj_lib::revset::RevsetWorkspaceContext;
 use jj_lib::revset::SymbolResolverExtension;
 use jj_lib::revset::UserRevsetExpression;
 use jj_lib::rewrite::restore_tree;
-use jj_lib::settings::ConfigResultExt as _;
 use jj_lib::settings::UserSettings;
 use jj_lib::str_util::StringPattern;
 use jj_lib::transaction::Transaction;
diff --git a/cli/src/commands/git/fetch.rs b/cli/src/commands/git/fetch.rs
index 0be1df9b6..9ec64b233 100644
--- a/cli/src/commands/git/fetch.rs
+++ b/cli/src/commands/git/fetch.rs
@@ -14,8 +14,8 @@
 
 use clap_complete::ArgValueCandidates;
 use itertools::Itertools;
+use jj_lib::config::ConfigResultExt as _;
 use jj_lib::repo::Repo;
-use jj_lib::settings::ConfigResultExt as _;
 use jj_lib::settings::UserSettings;
 use jj_lib::str_util::StringPattern;
 
diff --git a/cli/src/commands/git/push.rs b/cli/src/commands/git/push.rs
index 866dba265..bf3d8ea9e 100644
--- a/cli/src/commands/git/push.rs
+++ b/cli/src/commands/git/push.rs
@@ -21,6 +21,7 @@ use clap::ArgGroup;
 use clap_complete::ArgValueCandidates;
 use itertools::Itertools;
 use jj_lib::backend::CommitId;
+use jj_lib::config::ConfigResultExt as _;
 use jj_lib::git;
 use jj_lib::git::GitBranchPushTargets;
 use jj_lib::git::GitPushError;
@@ -32,7 +33,6 @@ use jj_lib::refs::BookmarkPushUpdate;
 use jj_lib::refs::LocalAndRemoteRef;
 use jj_lib::repo::Repo;
 use jj_lib::revset::RevsetExpression;
-use jj_lib::settings::ConfigResultExt as _;
 use jj_lib::settings::UserSettings;
 use jj_lib::str_util::StringPattern;
 use jj_lib::view::View;
diff --git a/cli/src/commands/log.rs b/cli/src/commands/log.rs
index c9409c42f..2009d9dd5 100644
--- a/cli/src/commands/log.rs
+++ b/cli/src/commands/log.rs
@@ -15,6 +15,7 @@
 use clap_complete::ArgValueCandidates;
 use jj_lib::backend::CommitId;
 use jj_lib::config::ConfigError;
+use jj_lib::config::ConfigResultExt as _;
 use jj_lib::graph::GraphEdgeType;
 use jj_lib::graph::ReverseGraphIterator;
 use jj_lib::graph::TopoGroupedGraphIterator;
@@ -23,7 +24,6 @@ use jj_lib::revset::RevsetEvaluationError;
 use jj_lib::revset::RevsetExpression;
 use jj_lib::revset::RevsetFilterPredicate;
 use jj_lib::revset::RevsetIteratorExt;
-use jj_lib::settings::ConfigResultExt as _;
 use jj_lib::settings::UserSettings;
 use tracing::instrument;
 
diff --git a/cli/src/commands/operation/log.rs b/cli/src/commands/operation/log.rs
index 22594340d..31d848c20 100644
--- a/cli/src/commands/operation/log.rs
+++ b/cli/src/commands/operation/log.rs
@@ -16,10 +16,10 @@ use std::slice;
 
 use itertools::Itertools as _;
 use jj_lib::config::ConfigError;
+use jj_lib::config::ConfigResultExt as _;
 use jj_lib::op_walk;
 use jj_lib::operation::Operation;
 use jj_lib::repo::RepoLoader;
-use jj_lib::settings::ConfigResultExt as _;
 use jj_lib::settings::UserSettings;
 
 use super::diff::show_op_diff;
diff --git a/cli/src/diff_util.rs b/cli/src/diff_util.rs
index 6d593da66..77187cacc 100644
--- a/cli/src/diff_util.rs
+++ b/cli/src/diff_util.rs
@@ -33,6 +33,7 @@ use jj_lib::backend::CopyRecord;
 use jj_lib::backend::TreeValue;
 use jj_lib::commit::Commit;
 use jj_lib::config::ConfigError;
+use jj_lib::config::ConfigResultExt as _;
 use jj_lib::conflicts::materialize_merge_result_to_bytes;
 use jj_lib::conflicts::materialized_diff_stream;
 use jj_lib::conflicts::ConflictMarkerStyle;
@@ -61,7 +62,6 @@ use jj_lib::repo_path::InvalidRepoPathError;
 use jj_lib::repo_path::RepoPath;
 use jj_lib::repo_path::RepoPathUiConverter;
 use jj_lib::rewrite::rebase_to_dest_parent;
-use jj_lib::settings::ConfigResultExt as _;
 use jj_lib::settings::UserSettings;
 use jj_lib::store::Store;
 use pollster::FutureExt;
diff --git a/cli/src/merge_tools/mod.rs b/cli/src/merge_tools/mod.rs
index d0ef9db61..83002607b 100644
--- a/cli/src/merge_tools/mod.rs
+++ b/cli/src/merge_tools/mod.rs
@@ -21,6 +21,7 @@ use std::sync::Arc;
 use jj_lib::backend::MergedTreeId;
 use jj_lib::config::ConfigError;
 use jj_lib::config::ConfigNamePathBuf;
+use jj_lib::config::ConfigResultExt as _;
 use jj_lib::conflicts::extract_as_single_hunk;
 use jj_lib::conflicts::ConflictMarkerStyle;
 use jj_lib::gitignore::GitIgnoreFile;
@@ -29,7 +30,6 @@ use jj_lib::merged_tree::MergedTree;
 use jj_lib::repo_path::InvalidRepoPathError;
 use jj_lib::repo_path::RepoPath;
 use jj_lib::repo_path::RepoPathBuf;
-use jj_lib::settings::ConfigResultExt as _;
 use jj_lib::settings::UserSettings;
 use jj_lib::working_copy::SnapshotError;
 use pollster::FutureExt;
diff --git a/lib/src/config.rs b/lib/src/config.rs
index eaebcd080..e69cb8333 100644
--- a/lib/src/config.rs
+++ b/lib/src/config.rs
@@ -36,6 +36,22 @@ pub type ConfigValue = config::Value;
 // TODO: will be replaced with our custom error type
 pub type ConfigError = config::ConfigError;
 
+/// Extension methods for `Result<T, ConfigError>`.
+pub trait ConfigResultExt<T> {
+    /// Converts `NotFound` error to `Ok(None)`, leaving other errors.
+    fn optional(self) -> Result<Option<T>, ConfigError>;
+}
+
+impl<T> ConfigResultExt<T> for Result<T, ConfigError> {
+    fn optional(self) -> Result<Option<T>, ConfigError> {
+        match self {
+            Ok(value) => Ok(Some(value)),
+            Err(ConfigError::NotFound(_)) => Ok(None),
+            Err(err) => Err(err),
+        }
+    }
+}
+
 /// Dotted config name path.
 #[derive(Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
 pub struct ConfigNamePathBuf(Vec<toml_edit::Key>);
diff --git a/lib/src/fsmonitor.rs b/lib/src/fsmonitor.rs
index 224cdec29..767620da2 100644
--- a/lib/src/fsmonitor.rs
+++ b/lib/src/fsmonitor.rs
@@ -25,7 +25,7 @@
 use std::path::PathBuf;
 
 use crate::config::ConfigError;
-use crate::settings::ConfigResultExt;
+use crate::config::ConfigResultExt as _;
 use crate::settings::UserSettings;
 
 /// Config for Watchman filesystem monitor (<https://facebook.github.io/watchman/>).
diff --git a/lib/src/gpg_signing.rs b/lib/src/gpg_signing.rs
index ff7ff4150..654b4ba68 100644
--- a/lib/src/gpg_signing.rs
+++ b/lib/src/gpg_signing.rs
@@ -26,7 +26,7 @@ use std::str;
 use thiserror::Error;
 
 use crate::config::ConfigError;
-use crate::settings::ConfigResultExt as _;
+use crate::config::ConfigResultExt as _;
 use crate::settings::UserSettings;
 use crate::signing::SigStatus;
 use crate::signing::SignError;
diff --git a/lib/src/settings.rs b/lib/src/settings.rs
index b4184da4d..6968690db 100644
--- a/lib/src/settings.rs
+++ b/lib/src/settings.rs
@@ -28,6 +28,7 @@ use crate::backend::Commit;
 use crate::backend::Signature;
 use crate::backend::Timestamp;
 use crate::config::ConfigError;
+use crate::config::ConfigResultExt as _;
 use crate::config::ConfigTable;
 use crate::config::ConfigValue;
 use crate::config::StackedConfig;
@@ -326,20 +327,6 @@ impl JJRng {
     }
 }
 
-pub trait ConfigResultExt<T> {
-    fn optional(self) -> Result<Option<T>, ConfigError>;
-}
-
-impl<T> ConfigResultExt<T> for Result<T, ConfigError> {
-    fn optional(self) -> Result<Option<T>, ConfigError> {
-        match self {
-            Ok(value) => Ok(Some(value)),
-            Err(ConfigError::NotFound(_)) => Ok(None),
-            Err(err) => Err(err),
-        }
-    }
-}
-
 /// A size in bytes optionally formatted/serialized with binary prefixes
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, serde::Deserialize)]
 #[serde(try_from = "String")]
diff --git a/lib/src/ssh_signing.rs b/lib/src/ssh_signing.rs
index 5ea9eb878..554b2fd2a 100644
--- a/lib/src/ssh_signing.rs
+++ b/lib/src/ssh_signing.rs
@@ -27,7 +27,7 @@ use either::Either;
 use thiserror::Error;
 
 use crate::config::ConfigError;
-use crate::settings::ConfigResultExt as _;
+use crate::config::ConfigResultExt as _;
 use crate::settings::UserSettings;
 use crate::signing::SigStatus;
 use crate::signing::SignError;