diff --git a/substreams/substream.py b/substreams/substream.py
index f86b96a..fe6e931 100644
--- a/substreams/substream.py
+++ b/substreams/substream.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 import base64
-import os
+import os, sys
 import subprocess
 from collections import defaultdict
 from dataclasses import dataclass
@@ -12,18 +12,19 @@
 import pandas as pd
 from google.protobuf.descriptor_pb2 import DescriptorProto
 from google.protobuf.json_format import MessageToDict
+from importlib import import_module
 
 DEFAULT_ENDPOINT = "api.streamingfast.io:443"
 
 
 def retrieve_class(module_name: str, class_name: str):
-    module = __import__(module_name)
+    module = import_module(module_name)
     return getattr(module, class_name)
 
 
-def generate_pb2_files(spkg_path: str, commands: str) -> None:
+def generate_pb2_files(spkg_path: str, commands: str, out_path: str) -> None:
     command = f"""
-    alias protogen_py="python3 -m grpc_tools.protoc --descriptor_set_in={spkg_path} --python_out=. --grpc_python_out=.";
+    alias protogen_py="python3 -m grpc_tools.protoc --descriptor_set_in={spkg_path} --python_out={out_path} --grpc_python_out={out_path}";
     {commands}
     unalias protogen_py;
     """
@@ -41,14 +42,17 @@ class SubstreamOutput:
 
 class Substream:
     def __init__(
-        self, spkg_path: str, token: Optional[str] = None, regenerate: bool = False
+        self, spkg_path: str, token: Optional[str] = None, regenerate: bool = False, sf_out_dir: str = '.'
     ):
         self.token: Optional[str] = os.getenv("SUBSTREAMS_API_TOKEN", None) or token
+        sf_dir_path = os.path.join(sf_out_dir, 'sf')
+        if not Path(sf_out_dir).exists():
+            os.makedirs(sf_out_dir)
         if not self.token:
             raise Exception("Must set SUBSTREAMS_API_TOKEN")
         if not Path(spkg_path).exists() or not spkg_path.endswith(".spkg"):
             raise Exception("Must provide a valid .spkg file!")
-        if not Path("sf/substreams").exists() or regenerate:
+        if not Path(sf_dir_path).exists() or regenerate:
             # generate sf/ directory
             commands = """
             protogen_py sf/substreams/v1/substreams.proto;
@@ -56,7 +60,9 @@ def __init__(
             protogen_py sf/substreams/v1/modules.proto;
             protogen_py sf/substreams/v1/clock.proto;
             """
-            generate_pb2_files(spkg_path, commands)
+            generate_pb2_files(spkg_path, commands, out_path=sf_out_dir)
+
+        sys.path.append(sf_out_dir)
 
         from sf.substreams.v1.package_pb2 import Package
         from sf.substreams.v1.substreams_pb2_grpc import StreamStub
@@ -72,7 +78,7 @@ def __init__(
                 if not file.startswith("sf/") and not file.startswith("google/")
             ]
         )
-        generate_pb2_files(spkg_path, custom_proto_files)
+        generate_pb2_files(spkg_path, custom_proto_files, out_path=sf_out_dir)
 
         credentials = grpc.composite_channel_credentials(
             grpc.ssl_channel_credentials(),
@@ -95,8 +101,7 @@ def _class_from_module(self, module_name: str):
         raw_module_path: str = self.proto_file_map.get(output_type)
         if raw_module_path is None:
             return None
-        module_path: str = raw_module_path.split("/")[-1].split(".proto")[0]
-        pb2_path: str = f"{module_path}_pb2"
+        pb2_path: str = raw_module_path.replace('.proto', '_pb2').replace('/', '.')
         return retrieve_class(pb2_path, output_type)
 
     def _parse_from_string(self, raw: str, key: str, output_class) -> dict: