diff --git a/.envrc b/.envrc
new file mode 100644
index 0000000..3550a30
--- /dev/null
+++ b/.envrc
@@ -0,0 +1 @@
+use flake
diff --git a/.gitignore b/.gitignore
index 4ebc8ae..dc894ff 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 coverage
+.direnv
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..6e99d27
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,61 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1710146030,
+        "narHash": "sha256-SZ5L6eA7HJ/nmkzGG7/ISclqe6oZdOZTNoesiInkXPQ=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "b1d9ab70662946ef0850d488da1c9019f3a9752a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1723175592,
+        "narHash": "sha256-M0xJ3FbDUc4fRZ84dPGx5VvgFsOzds77KiBMW/mMTnI=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "5e0ca22929f3342b19569b21b2f3462f053e497b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..2433017
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,36 @@
+{
+  description = "A flake for bash, coreutils, xxd, restic, util-linux, and openssh";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = {
+    self,
+    nixpkgs,
+    flake-utils,
+  }:
+    flake-utils.lib.eachDefaultSystem (
+      system: let
+        pkgs = nixpkgs.legacyPackages.${system};
+      in {
+        devShell = pkgs.mkShell {
+          buildInputs = with pkgs; [
+            bash
+            coreutils
+            kcov
+            vim # provides xxd
+            python3
+            python312Packages.fusepy
+            restic
+            screen
+            shellcheck
+            tmux
+            utillinux
+            openssh
+          ];
+        };
+      }
+    );
+}
diff --git a/test/test.sh b/test/test.sh
index 5935aab..3690347 100755
--- a/test/test.sh
+++ b/test/test.sh
@@ -50,7 +50,7 @@ assert-equals-directory () {
   fi
   if [ -d "$1" ]; then
     for FILE in "$1"/*; do
-      assert-equals-directory "$FILE" "$2/${FILE##$1}"
+      assert-equals-directory "$FILE" "$2/${FILE##"$1"}"
     done
   else
     assertEquals "$(cat "$1")" "$(cat "$2")"
@@ -136,8 +136,6 @@ test-file-changed-as-read-warning () {
   assert-equals-directory "$WORLD_DIR/file3.txt" "$TEST_TMP/restored/$WORLD_DIR/file3.txt"
 }
 
-
-
 test-lock-defaults () {
   TIMESTAMP="$(date +%F_%H-%M-%S --date="2021-01-01")"
   ./backup.sh -t "$TEST_TMP/lockfile" -i "$TEST_TMP/server/world" -o "$TEST_TMP/backups" -s "$SCREEN_TMP" -f "$TIMESTAMP"
@@ -241,7 +239,6 @@ test-restic-defaults () {
   check-latest-backup-restic
 }
 
-
 test-backup-spaces-in-directory () {
   TIMESTAMP="$(date +%F_%H-%M-%S --date="2021-01-01")"
   WORLD_SPACES="$TEST_TMP/minecraft server/the world"
@@ -513,10 +510,14 @@ test-restic-thinning-delete () {
   done
   UNEXPECTED_TIMESTAMPS=(
     "2021-01-01 00:00:00"
+    "2021-01-01 01:00:00"
+    "2021-01-01 02:00:00"
     "2021-01-02 22:00:00"
+    "2021-01-03 22:00:00"
+    "2021-01-04 00:00:00"
   )
   for TIMESTAMP in "${UNEXPECTED_TIMESTAMPS[@]}"; do
-    assertNotContains "$SNAPSHOTS" "$TIMESTAMP" 
+    assertNotContains "$SNAPSHOTS" "$TIMESTAMP"
   done
 }