diff --git a/tests/test_external.py b/tests/test_external.py
index 14e5b20..cd7fddb 100644
--- a/tests/test_external.py
+++ b/tests/test_external.py
@@ -1,8 +1,12 @@
+from __future__ import annotations
+
 # built-in
+import string
 from math import isclose
 
 # external
 import hypothesis
+import hypothesis.strategies
 import pytest
 
 # project
@@ -22,6 +26,12 @@
 )
 def test_compare(left, right, alg):
     for lib in libraries.get_libs(alg):
+
+        if lib.module_name == 'jellyfish':
+            ascii = set(string.printable)
+            if (set(left) | set(right)) - ascii:
+                continue
+
         conditions = lib.conditions or {}
         internal_func = getattr(textdistance, alg)(external=False, **conditions)
         external_func = lib.get_function()
@@ -44,8 +54,14 @@ def test_compare(left, right, alg):
     right=hypothesis.strategies.text(min_size=1),
 )
 @pytest.mark.parametrize('qval', (None, 1, 2, 3))
-def test_qval(left, right, alg, qval):
+def test_qval(left: str, right: str, alg: str, qval: int | None) -> None:
     for lib in libraries.get_libs(alg):
+
+        if lib.module_name == 'jellyfish':
+            ascii = set(string.printable)
+            if (set(left) | set(right)) - ascii:
+                continue
+
         conditions = lib.conditions or {}
         internal_func = getattr(textdistance, alg)(external=False, **conditions)
         external_func = lib.get_function()
diff --git a/textdistance/libraries.py b/textdistance/libraries.py
index a0b9c16..23d9393 100644
--- a/textdistance/libraries.py
+++ b/textdistance/libraries.py
@@ -39,12 +39,12 @@ def optimize(self) -> None:
             # sort libs by speed
             self.libs[alg].sort(key=lambda lib: libs_names.index([lib.module_name, lib.func_name]))
 
-    def get_algorithms(self) -> list:
+    def get_algorithms(self) -> list[str]:
         """Get list of available algorithms.
         """
         return list(self.libs.keys())
 
-    def get_libs(self, alg) -> list[LibraryBase]:
+    def get_libs(self, alg: str) -> list[LibraryBase]:
         """Get libs list for algorithm
         """
         if alg not in self.libs:
@@ -69,7 +69,7 @@ def __init__(
         *,
         presets: dict[str, Any] | None = None,
         attr: str | None = None,
-        conditions: dict[str, Any] | None = None,
+        conditions: dict[str, bool] | None = None,
     ) -> None:
         self.module_name = module_name
         self.func_name = func_name
@@ -89,7 +89,7 @@ def check_conditions(self, obj: object, *sequences: Sequence) -> bool:
 
         return True
 
-    def prepare(self, *sequences) -> tuple:
+    def prepare(self, *sequences: Sequence) -> tuple:
         return sequences
 
     @property
@@ -128,7 +128,7 @@ def __str__(self) -> str:
 
 
 class TextLibrary(LibraryBase):
-    def check_conditions(self, obj, *sequences: Sequence) -> bool:
+    def check_conditions(self, obj: object, *sequences: Sequence) -> bool:
         if not super().check_conditions(obj, *sequences):
             return False
 
@@ -142,7 +142,7 @@ def check_conditions(self, obj, *sequences: Sequence) -> bool:
                 return False
         return True
 
-    def prepare(self, *sequences) -> tuple:
+    def prepare(self, *sequences: Sequence) -> tuple:
         # convert list of letters to string
         if isinstance(sequences[0], (tuple, list)):
             sequences = tuple(map(lambda x: ''.join(x), sequences))
@@ -150,7 +150,7 @@ def prepare(self, *sequences) -> tuple:
 
 
 class SameLengthLibrary(LibraryBase):
-    def check_conditions(self, obj, *sequences: Sequence) -> bool:
+    def check_conditions(self, obj: object, *sequences: Sequence) -> bool:
         if not super().check_conditions(obj, *sequences):
             return False
         # compare only same length iterators