diff --git a/nixpkgs_review/cli/wip.py b/nixpkgs_review/cli/wip.py
index 6377d7e..9fba5e1 100644
--- a/nixpkgs_review/cli/wip.py
+++ b/nixpkgs_review/cli/wip.py
@@ -11,7 +11,7 @@ def wip_command(args: argparse.Namespace) -> Path:
     allow = AllowedFeatures(args.allow)
     with Buildenv(allow.aliases, args.extra_nixpkgs_config) as nixpkgs_config:
         return review_local_revision(
-            "rev-%s-dirty" % verify_commit_hash("HEAD"),
+            f"rev-{verify_commit_hash('HEAD')}-dirty",
             args,
             allow,
             nixpkgs_config,
diff --git a/nixpkgs_review/review.py b/nixpkgs_review/review.py
index ff2885c..278b1ab 100644
--- a/nixpkgs_review/review.py
+++ b/nixpkgs_review/review.py
@@ -147,7 +147,7 @@ def apply_unstaged(self, staged: bool = False) -> None:
         result = subprocess.run(["git", "apply"], cwd=self.worktree_dir(), input=diff)
 
         if result.returncode != 0:
-            warn("Failed to apply diff in %s" % self.worktree_dir())
+            warn(f"Failed to apply diff in {self.worktree_dir()}")
             sys.exit(1)
 
     def build_commit(
@@ -396,8 +396,7 @@ def list_packages(
         res = subprocess.run(cmd, stdout=tmp)
         if res.returncode != 0:
             raise NixpkgsReviewError(
-                "Failed to list packages: nix-env failed with exit code %d"
-                % res.returncode
+                f"Failed to list packages: nix-env failed with exit code {res.returncode}"
             )
         tmp.flush()
         with open(tmp.name, encoding="utf-8") as f: