diff --git a/outlines/fsm/guide.py b/outlines/fsm/guide.py
index cf5be8d50..fa824449a 100644
--- a/outlines/fsm/guide.py
+++ b/outlines/fsm/guide.py
@@ -5,7 +5,6 @@
 from lark import Lark
 
 from outlines import grammars
-from outlines.caching import cache
 from outlines.fsm.regex import (
     create_fsm_index_tokenizer,
     make_byte_level_fsm,
@@ -110,7 +109,6 @@ class RegexGuide(Guide):
     initial_state = 0
 
     def __init__(self, regex_string: str, tokenizer):
-        @cache()
         def create_states_mapping(regex_string: str) -> Tuple[dict, set, set]:
             """Create the variables related to the mapping between states and tokens
             The parameters of the function are used for caching purpose
@@ -120,9 +118,7 @@ def create_states_mapping(regex_string: str) -> Tuple[dict, set, set]:
                 regex_pattern.to_fsm().reduce(), keep_utf8=True
             )
             regex_fsm, _ = make_deterministic_fsm(byte_fsm)
-            states_to_token_maps, empty_token_ids = create_fsm_index_tokenizer(
-                regex_fsm, tokenizer
-            )
+            states_to_token_maps, _ = create_fsm_index_tokenizer(regex_fsm, tokenizer)
 
             # We make sure that it is possible to generate strings in the language
             # of the regular expression with the tokens present in the model's
@@ -135,11 +131,10 @@ def create_states_mapping(regex_string: str) -> Tuple[dict, set, set]:
                     "The vocabulary does not allow us to build a sequence that matches the input regex"
                 )
 
-            return states_to_token_maps, empty_token_ids, regex_fsm.finals
+            return states_to_token_maps, regex_fsm.finals
 
         (
             self.states_to_token_maps,
-            self.empty_token_ids,
             fsm_finals,
         ) = create_states_mapping(regex_string)
         self.eos_token_id = tokenizer.eos_token_id
@@ -220,9 +215,7 @@ def create_states_mapping_from_interegular_fsm(
             """
             byte_fsm = make_byte_level_fsm(fsm.reduce(), keep_utf8=True)
             regex_fsm, _ = make_deterministic_fsm(byte_fsm)
-            states_to_token_maps, empty_token_ids = create_fsm_index_tokenizer(
-                regex_fsm, tokenizer
-            )
+            states_to_token_maps, _ = create_fsm_index_tokenizer(regex_fsm, tokenizer)
 
             # We make sure that it is possible to generate strings in the language
             # of the regular expression with the tokens present in the model's
@@ -235,11 +228,10 @@ def create_states_mapping_from_interegular_fsm(
                     "The vocabulary does not allow us to build a sequence that matches the input regex"
                 )
 
-            return states_to_token_maps, empty_token_ids
+            return states_to_token_maps
 
         (
             from_interegular_instance.states_to_token_maps,
-            from_interegular_instance.empty_token_ids,
         ) = create_states_mapping_from_interegular_fsm(interegular_fsm)
         from_interegular_instance.eos_token_id = tokenizer.eos_token_id
         return from_interegular_instance
diff --git a/outlines/fsm/regex.py b/outlines/fsm/regex.py
index 0941bbb9f..5242aea92 100644
--- a/outlines/fsm/regex.py
+++ b/outlines/fsm/regex.py
@@ -1,6 +1,5 @@
 import re
 from collections import namedtuple
-from functools import lru_cache
 from typing import (
     TYPE_CHECKING,
     Dict,
@@ -112,7 +111,7 @@ def fsm_info(self):
 nb_unichar_2_type = numba.types.UnicodeCharSeq(2)
 
 
-@numba.njit(cache=True)
+@numba.njit(cache=False)
 def create_fsm_info(
     py_initial,
     py_finals,
@@ -411,7 +410,7 @@ def make_deterministic_fsm(fsm: FSM) -> Tuple[BetterFSM, Dict[int, int]]:
     return new_fsm, old_to_new_states
 
 
-@numba.njit(nogil=True, cache=True)
+@numba.njit(nogil=True, cache=False)
 def _walk_fsm(
     fsm_transitions: Dict[Tuple[int, int], int],
     alphabet_symbol_mapping: Dict[str, int],
@@ -647,7 +646,7 @@ def get_sub_fsms_from_seq(
     )
 
 
-@numba.njit(cache=True, nogil=True)
+@numba.njit(cache=False, nogil=True)
 def state_scan_tokens(
     fsm_transitions: Dict[Tuple[int, int], int],
     alphabet_symbol_mapping: Dict[str, int],
@@ -723,7 +722,6 @@ def create_fsm_index_end_to_end(
 
 
 # Copied from transformers.models.gpt2.tokenization_gpt2.bytes_to_unicode
-@lru_cache()
 def gpt2_bytes_to_unicode():
     """
     Returns list of utf-8 byte and a mapping to unicode strings. We specifically avoids mapping to whitespace/control
@@ -750,14 +748,12 @@ def gpt2_bytes_to_unicode():
     return dict(zip(bs, cs))
 
 
-@lru_cache()
 def gpt2_unicode_to_bytes():
     return {v: k for k, v in gpt2_bytes_to_unicode().items()}
 
 
 # TODO: Cannot cache typed collections to disk, yet.  See
 # https://github.com/numba/numba/issues/4698
-@lru_cache
 def reduced_vocabulary(
     tokenizer: "Tokenizer",
 ) -> Tuple[List[Tuple[Sequence[str], Sequence[int]]], Set[int]]:
diff --git a/outlines/models/vllm.py b/outlines/models/vllm.py
index 378a35d91..038c80e60 100644
--- a/outlines/models/vllm.py
+++ b/outlines/models/vllm.py
@@ -1,7 +1,9 @@
+import concurrent.futures
 import dataclasses
 from typing import TYPE_CHECKING, List, Optional, Union
 
 from outlines.generate.api import GenerationParameters, SamplingParameters
+from outlines.integrations.utils import adapt_tokenizer
 
 if TYPE_CHECKING:
     from vllm import LLM
@@ -18,7 +20,7 @@ class VLLM:
 
     """
 
-    def __init__(self, model: "LLM"):
+    def __init__(self, model: "LLM", tokenizer):
         self.model = model
         self.lora_request = None
 
@@ -73,6 +75,9 @@ def generate(
         # are specified by the user when calling the generator.
         if max_tokens is not None:
             sampling_params.max_tokens = max_tokens
+        else:
+            sampling_params.max_tokens = None
+
         if stop_at is not None:
             if isinstance(stop_at, str):
                 stop_at = [stop_at]
@@ -140,7 +145,40 @@ def load_lora(self, adapter_path: Optional[str]):
             self.lora_request = LoRARequest(adapter_path, 1, adapter_path)
 
 
-def vllm(model_name: str, **vllm_model_params):
+def load_model(model_name, **vllm_model_params):
+    """Load the model in GPU memory."""
+    from vllm import LLM
+
+    model = LLM(model_name, **vllm_model_params)
+    return model
+
+
+def load_and_convert_tokenizer(model_name):
+    """Convert vocabulary types and JIT-compile function."""
+    from transformers import AutoTokenizer
+
+    tokenizer = AutoTokenizer.from_pretrained(model_name)
+    tokenizer = convert_tokenizer(tokenizer)
+    jit_compile_numba(tokenizer.numba_vocabulary)
+
+    return tokenizer
+
+
+def convert_tokenizer(tokenizer):
+    from outlines.fsm.regex import reduced_vocabulary
+
+    tokenizer = adapt_tokenizer(tokenizer)
+    vocabulary, _ = reduced_vocabulary(tokenizer)
+    tokenizer.vocabulary_numba = vocabulary
+
+    return tokenizer
+
+
+def jit_compile_numba(vocabulary):
+    pass
+
+
+def vllm(model_or_model_name: Union[str, "LLM"], **vllm_model_params):
     """Load a vLLM model.
 
     Arguments
@@ -154,6 +192,16 @@ def vllm(model_name: str, **vllm_model_params):
     """
     from vllm import LLM
 
-    model = LLM(model_name, **vllm_model_params)
+    if isinstance(model_or_model_name, LLM):
+        model = model_or_model_name
+        tokenizer = convert_tokenizer(model.tokenizer)
+    else:
+        with concurrent.futures.ThreadPoolExecutor() as executor:
+            model_name = model_or_model_name
+            future_model = executor.submit(load_model, model_name, **vllm_model_params)
+            future_tokenizer = executor.submit(load_and_convert_tokenizer, model_name)
+
+            tokenizer = future_tokenizer.result()
+            model = future_model.result()
 
-    return VLLM(model)
+    return VLLM(model, tokenizer)
diff --git a/profile.py b/profile.py
new file mode 100644
index 000000000..cd2824b11
--- /dev/null
+++ b/profile.py
@@ -0,0 +1,54 @@
+import interegular
+import line_profiler
+from transformers import SPIECE_UNDERLINE
+
+from outlines import generate, models
+from outlines.fsm.regex import (
+    _walk_fsm,
+    create_fsm_index_end_to_end,
+    create_fsm_index_tokenizer,
+    make_byte_level_fsm,
+    make_deterministic_fsm,
+    reduced_vocabulary,
+    state_scan_tokens,
+)
+
+
+def run_model():
+    model = models.vllm(
+        "TheBloke/Mistral-7B-Instruct-v0.2-GPTQ", quantization="gptq", dtype="half"
+    )
+    tokenizer = model.model.get_tokenizer()
+    tokenizer.vocabulary = tokenizer.get_vocab()
+    tokenizer.special_tokens = set(tokenizer.all_special_tokens)
+
+    def convert_token_to_string(token):
+        string = tokenizer.convert_tokens_to_string([token])
+
+        # A hack to handle missing spaces to HF's Llama tokenizers
+        if (
+            type(token) is str
+            and token.startswith(SPIECE_UNDERLINE)
+            or token == "<0x20>"
+        ):
+            return " " + string
+
+        return string
+
+    tokenizer.convert_token_to_string = convert_token_to_string
+
+    regex_string = '\\{[\n ]*"name"[\n ]*:[\n ]*"(?:[^"\\\x00-\x1f\x7f-\x9f]|\\.){,10}"[\n ]*,[\n ]*"age"[\n ]*:[\n ]*(0|[1-9][0-9]*)[\n ]*,[\n ]*"armor"[\n ]*:[\n ]*("leather"|"chainmail"|"plate")[\n ]*,[\n ]*"strength"[\n ]*:[\n ]*(0|[1-9][0-9]*)[\n ]*\\}'
+    regex_pattern = interegular.parse_pattern(regex_string)
+    byte_fsm = make_byte_level_fsm(regex_pattern.to_fsm().reduce(), keep_utf8=True)
+    regex_fsm, _ = make_deterministic_fsm(byte_fsm)
+    states_to_token_maps, empty_token_ids = create_fsm_index_tokenizer(
+        regex_fsm, tokenizer
+    )
+
+
+profile = line_profiler.LineProfiler()
+profile.add_function(create_fsm_index_tokenizer)
+profile.add_function(create_fsm_index_end_to_end)
+profile.add_function(reduced_vocabulary)
+profile(run_model)()
+profile.print_stats()