diff --git a/.github/workflows/dylint.yml b/.github/workflows/dylint.yml
index a7ac4e4e..c3df7e2f 100644
--- a/.github/workflows/dylint.yml
+++ b/.github/workflows/dylint.yml
@@ -125,7 +125,7 @@ jobs:
       - name: Prepare prebuilt Dylint tools and driver
         timeout-minutes: 10
         run: |
-          soldr dylint prepare 2>&1 | tee "$RUNNER_TEMP/dylint-prepare.log"
+          env -u RUSTUP_TOOLCHAIN soldr dylint prepare 2>&1 | tee "$RUNNER_TEMP/dylint-prepare.log"
           # Library UI tests invoke soldr cargo test separately, so preserve
           # the prebuilt dylint-link directory for their linker config.
           sed -n 's/^soldr: dylint prepare: tool bin dir //p' "$RUNNER_TEMP/dylint-prepare.log" >> "$GITHUB_PATH"
@@ -192,7 +192,7 @@ jobs:
           # every platform-gated source path on each run.
           export RUSTFLAGS="${RUSTFLAGS:+${RUSTFLAGS} }--cfg fbuild_platform_boundary_observation_run_${GITHUB_RUN_ID}"
           rm -f "$FBUILD_PLATFORM_BOUNDARY_OBSERVED"
-          soldr dylint --all -- --workspace --all-targets
+          env -u RUSTUP_TOOLCHAIN soldr dylint --all -- --workspace --all-targets
       - name: Compare scanner with actual Dylint observations
         run: uv run --no-project python ci/enforce_platform_boundary.py --dylint-observed target/platform-boundary-dylint-observed.tsv --print-totals
 
diff --git a/ci/run_dylint.py b/ci/run_dylint.py
index a843a523..681f23e4 100644
--- a/ci/run_dylint.py
+++ b/ci/run_dylint.py
@@ -24,6 +24,9 @@ def main(argv: list[str] | None = None) -> int:
     if not os.environ.get("CARGO_HOME"):
         os.environ["CARGO_HOME"] = str(Path.home() / ".cargo")
     env = os.environ.copy()
+    # setup-soldr pins the workspace's stable toolchain in this variable.
+    # Dylint must resolve the separate nightly from its library manifests.
+    env.pop("RUSTUP_TOOLCHAIN", None)
     # The ordinary local check can reuse Cargo fingerprints. CI's native OS
     # legs force fresh traversal and compare the independent observation ledger.
     env.pop("FBUILD_PLATFORM_BOUNDARY_OBSERVED", None)
diff --git a/ci/test_run_dylint.py b/ci/test_run_dylint.py
index 984350de..408514f3 100644
--- a/ci/test_run_dylint.py
+++ b/ci/test_run_dylint.py
@@ -14,11 +14,12 @@ def test_prepares_prebuilt_tools_and_lints_workspace(self) -> None:
         commands: list[list[str]] = []
 
         def run(args: list[str], **_kwargs):
+            self.assertNotIn("RUSTUP_TOOLCHAIN", _kwargs["env"])
             commands.append(args)
             return subprocess.CompletedProcess(args, 0)
 
         with (
-            patch.dict(os.environ, {"CARGO_HOME": "", "FBUILD_PLATFORM_BOUNDARY_OBSERVED": "stale"}),
+            patch.dict(os.environ, {"CARGO_HOME": "", "FBUILD_PLATFORM_BOUNDARY_OBSERVED": "stale", "RUSTUP_TOOLCHAIN": "1.95.0"}),
             patch.object(Path, "home", return_value=Path("/tmp/fbuild-test-home")),
             patch.object(run_dylint, "activate"),
             patch.object(run_dylint.subprocess, "run", side_effect=run),