diff --git a/codespell_lib/tests/test_dictionary.py b/codespell_lib/tests/test_dictionary.py
index 99db815160..21e84a85c6 100644
--- a/codespell_lib/tests/test_dictionary.py
+++ b/codespell_lib/tests/test_dictionary.py
@@ -20,11 +20,11 @@
     if os.getenv("REQUIRE_ASPELL", "false").lower() == "true":
         raise RuntimeError(
             "Cannot run complete tests without aspell when "
-            "REQUIRE_ASPELL=true. Got error during import:\n{}".format(exp)
+            f"REQUIRE_ASPELL=true. Got error during import:\n{exp}"
         )
     warnings.warn(
         "aspell not found, but not required, skipping aspell tests. Got "
-        "error during import:\n{}".format(exp),
+        f"error during import:\n{exp}",
         stacklevel=2,
     )
 
@@ -277,10 +277,9 @@ def test_dictionary_looping(
         for line in fid:
             err, rep = line.split("->")
             err = err.lower()
-            assert err not in this_err_dict, "error {!r} already exists in {}".format(
-                err,
-                short_fname,
-            )
+            assert (
+                err not in this_err_dict
+            ), f"error {err:!r} already exists in {short_fname}"
             rep = rep.rstrip("\n")
             reps = [r.strip() for r in rep.lower().split(",")]
             reps = [r for r in reps if len(r)]
@@ -289,8 +288,8 @@ def test_dictionary_looping(
     for err in this_err_dict:
         for r in this_err_dict[err]:
             assert r not in this_err_dict, (
-                "error {}: correction {} is an error itself in the same "
-                "dictionary file {}".format(err, r, short_fname)
+                f"error {err}: correction {r} is an error itself "
+                f"in the same dictionary file {short_fname}"
             )
     pair = (short_fname, short_fname)
     assert pair not in global_pairs
@@ -298,29 +297,22 @@ def test_dictionary_looping(
     for other_fname, other_err_dict in global_err_dicts.items():
         # error duplication (eventually maybe we should just merge?)
         for err in this_err_dict:
-            assert (
-                err not in other_err_dict
-            ), "error {!r} in dictionary {} already exists in dictionary {}".format(
-                err,
-                short_fname,
-                other_fname,
+            assert err not in other_err_dict, (
+                f"error {err:!r} in dictionary {short_fname} "
+                f"already exists in dictionary {other_fname}"
             )
         # 2. check corrections in this dict against other dicts (upper)
         pair = (short_fname, other_fname)
         if pair not in allowed_dups:
             for err in this_err_dict:
-                assert (
-                    err not in other_err_dict
-                ), "error {!r} in dictionary {} already exists in dictionary {}".format(
-                    err,
-                    short_fname,
-                    other_fname,
+                assert err not in other_err_dict, (
+                    f"error {err:!r} in dictionary {short_fname} "
+                    f"already exists in dictionary {other_fname}"
                 )
                 for r in this_err_dict[err]:
                     assert r not in other_err_dict, (
-                        "error %s: correction %s from dictionary %s is an "
-                        "error itself in dictionary %s"
-                        % (err, r, short_fname, other_fname)
+                        f"error {err}: correction {r} from dictionary {short_fname} "
+                        f"is an error itself in dictionary {other_fname}"
                     )
         assert pair not in global_pairs
         global_pairs.add(pair)
@@ -330,9 +322,8 @@ def test_dictionary_looping(
             for err in other_err_dict:
                 for r in other_err_dict[err]:
                     assert r not in this_err_dict, (
-                        "error %s: correction %s from dictionary %s is an "
-                        "error itself in dictionary %s"
-                        % (err, r, other_fname, short_fname)
+                        f"error {err}: correction {r} from dictionary {other_fname} "
+                        f"is an error itself in dictionary {short_fname}"
                     )
         assert pair not in global_pairs
         global_pairs.add(pair)