diff --git a/.evergreen/run-mongodb-aws-ecs-test.sh b/.evergreen/run-mongodb-aws-ecs-test.sh
index 5c047548a4..c823ed3c33 100755
--- a/.evergreen/run-mongodb-aws-ecs-test.sh
+++ b/.evergreen/run-mongodb-aws-ecs-test.sh
@@ -19,17 +19,17 @@ fi
 # Now we can safely enable xtrace
 set -o xtrace
 
-# Install a c compiler.
+# Install a C compiler (for the C extensions) and git (needed by uv to
+# resolve the mockupdb git dependency)
 apt-get -qq update  < /dev/null > /dev/null
-apt-get -q install -y build-essential
+apt-get -q install -y build-essential git
 
 export SET_XTRACE_ON=1
 export CI=true
-# This container has no git, so uv must never try to resolve the mockupdb
-# git dependency; UV_NO_LOCK makes uv ignore any lock file entirely.
-export UV_NO_LOCK=1
 cd src
 rm -rf .venv
+# Discard any lockfile written by the host so we resolve from scratch
+rm -f uv.lock
 rm -f .evergreen/scripts/test-env.sh || true
 rm -f .evergreen/scripts/env.sh || true
 bash ./.evergreen/just.sh setup-tests auth_aws ecs-remote
diff --git a/.evergreen/run-tests.sh b/.evergreen/run-tests.sh
index fc9d07b6b1..4ec527c941 100755
--- a/.evergreen/run-tests.sh
+++ b/.evergreen/run-tests.sh
@@ -27,8 +27,6 @@ else
 fi
 
 # Start the test runner.
-# Never create or read a uv.lock; hosts without git can't resolve mockupdb.
-export UV_NO_LOCK=1
 echo "Running tests with UV_PYTHON=${UV_PYTHON:-}..."
 echo "UV_ARGS=${UV_ARGS}"
 uv run ${UV_ARGS} --reinstall-package pymongo .evergreen/scripts/run_tests.py "$@"
diff --git a/.evergreen/scripts/configure-env.sh b/.evergreen/scripts/configure-env.sh
index 54ddc4c136..8dc328aab3 100755
--- a/.evergreen/scripts/configure-env.sh
+++ b/.evergreen/scripts/configure-env.sh
@@ -65,7 +65,6 @@ export CARGO_HOME="$CARGO_HOME"
 export UV_TOOL_DIR="$UV_TOOL_DIR"
 export UV_CACHE_DIR="$UV_CACHE_DIR"
 export UV_TOOL_BIN_DIR="$DRIVERS_TOOLS_BINARIES"
-export UV_NO_LOCK=1
 export PYMONGO_BIN_DIR="$PYMONGO_BIN_DIR"
 export PATH="$PATH_EXT"
 # shellcheck disable=SC2154
diff --git a/.evergreen/scripts/kms_tester.py b/.evergreen/scripts/kms_tester.py
index 1c2a39ad39..910df26b89 100644
--- a/.evergreen/scripts/kms_tester.py
+++ b/.evergreen/scripts/kms_tester.py
@@ -33,9 +33,7 @@ def _setup_azure_vm(base_env: dict[str, str]) -> None:
     env["AZUREKMS_CMD"] = "sudo apt-get install -y python3-dev build-essential"
     run_command(f"{azure_dir}/run-command.sh", env=env)
 
-    env["AZUREKMS_CMD"] = (
-        "CI=true UV_NO_LOCK=1 bash .evergreen/just.sh setup-tests kms azure-remote"
-    )
+    env["AZUREKMS_CMD"] = "CI=true bash .evergreen/just.sh setup-tests kms azure-remote"
     run_command(f"{azure_dir}/run-command.sh", env=env)
     LOGGER.info("Setting up Azure VM... done.")
 
@@ -55,7 +53,7 @@ def _setup_gcp_vm(base_env: dict[str, str]) -> None:
     env["GCPKMS_CMD"] = "sudo apt-get install -y python3-dev build-essential"
     run_command(f"{gcp_dir}/run-command.sh", env=env)
 
-    env["GCPKMS_CMD"] = "CI=true UV_NO_LOCK=1 bash ./.evergreen/just.sh setup-tests kms gcp-remote"
+    env["GCPKMS_CMD"] = "CI=true bash ./.evergreen/just.sh setup-tests kms gcp-remote"
     run_command(f"{gcp_dir}/run-command.sh", env=env)
     LOGGER.info("Setting up GCP VM...")
 
@@ -132,10 +130,10 @@ def test_kms_send_to_remote(sub_test_name: str) -> None:
         key_name = os.environ["KEY_NAME"]
         key_vault_endpoint = os.environ["KEY_VAULT_ENDPOINT"]
         env["AZUREKMS_CMD"] = (
-            f'KEY_NAME="{key_name}" KEY_VAULT_ENDPOINT="{key_vault_endpoint}" CI=true UV_NO_LOCK=1 bash ./.evergreen/just.sh run-tests'
+            f'KEY_NAME="{key_name}" KEY_VAULT_ENDPOINT="{key_vault_endpoint}" CI=true bash ./.evergreen/just.sh run-tests'
         )
     else:
-        env["GCPKMS_CMD"] = "CI=true UV_NO_LOCK=1 ./.evergreen/just.sh run-tests"
+        env["GCPKMS_CMD"] = "CI=true ./.evergreen/just.sh run-tests"
     cmd = f"{DIRS[sub_test_name]}/run-command.sh"
     run_command(cmd, env=env)
 
diff --git a/.evergreen/scripts/setup-tests.sh b/.evergreen/scripts/setup-tests.sh
index 714eee9162..858906a39e 100755
--- a/.evergreen/scripts/setup-tests.sh
+++ b/.evergreen/scripts/setup-tests.sh
@@ -21,9 +21,6 @@ if [ -f $SCRIPT_DIR/env.sh ]; then
   source $SCRIPT_DIR/env.sh
 fi
 
-# Never create or read a uv.lock; hosts without git can't resolve mockupdb.
-export UV_NO_LOCK=1
-
 echo "Setting up tests with args \"$*\"..."
 uv run ${USE_ACTIVE_VENV:+--active} "$SCRIPT_DIR/setup_tests.py" "$@"
 echo "Setting up tests with args \"$*\"... done."
diff --git a/.github/workflows/test-python.yml b/.github/workflows/test-python.yml
index b288516b68..be31421289 100644
--- a/.github/workflows/test-python.yml
+++ b/.github/workflows/test-python.yml
@@ -17,9 +17,6 @@ defaults:
 permissions:
   contents: read
 
-env:
-  UV_NO_LOCK: "1"
-
 jobs:
 
   static:
diff --git a/justfile b/justfile
index f6f10ca5a9..df678cdbac 100644
--- a/justfile
+++ b/justfile
@@ -1,9 +1,6 @@
 # See https://just.systems/man/en/ for instructions
 set shell := ["bash", "-c"]
 
-# Don't let `uv` create or read uv.lock.
-export UV_NO_LOCK := "1"
-
 # Commonly used command segments.
 typing_run := "uv run --group typing --extra aws --extra encryption --with numpy --extra ocsp --extra snappy --extra test --extra zstd"
 docs_run := "uv run --extra docs"
diff --git a/pyproject.toml b/pyproject.toml
index dc3c098906..571e1a4778 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -47,9 +47,6 @@ Source = "https://github.com/mongodb/mongo-python-driver"
 Tracker = "https://jira.mongodb.org/projects/PYTHON/issues"
 
 [tool.uv]
-# Only sync the (empty) dev group by default; groups like mockupdb require
-# an explicit --group flag so hosts without git aren't forced to resolve it.
-default-groups = ["dev"]
 # Wait 7 days before resolving newly published package versions.
 exclude-newer = "7 days"