diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 913c735..68e0815 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -14,7 +14,12 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: cachix/install-nix-action@v27
+      # v27 pins Nix 2.22.1, which is old enough to mis-evaluate flake input
+      # overrides that newer Nix handles fine (notably nested
+      # `a.inputs.b.inputs.c.follows`, which 2.22 rejects with "cannot find
+      # flake in the flake registries"). v31 pins 2.35.1. Keep this in step
+      # with logos-standalone-app, which already runs v31 for the same reason.
+      - uses: cachix/install-nix-action@v31
         with:
           extra_nix_config: |
             experimental-features = nix-command flakes
diff --git a/flake.lock b/flake.lock
index 8a6b548..0f096e2 100644
--- a/flake.lock
+++ b/flake.lock
@@ -55,11 +55,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1785523697,
-        "narHash": "sha256-8WdoCJDLNR/aLkcmeY8CeAZlTIN8ulG/7N1ZFEVDdsQ=",
+        "lastModified": 1786030193,
+        "narHash": "sha256-Z5rxmZBMJsNsUSb37ljbDMKrtrds9Enw5oPJcf8wbVU=",
         "owner": "logos-co",
         "repo": "logos-protocol",
-        "rev": "3a31c91d1322dae053bbe28b6e3f441fabcc2162",
+        "rev": "0f26ffdeef18fb9582dc0a95e2bee482464da40d",
         "type": "github"
       },
       "original": {