diff --git a/.python-version b/.python-version
index 43077b2..c8cfe39 100644
--- a/.python-version
+++ b/.python-version
@@ -1 +1 @@
-3.9.18
+3.10
diff --git a/examples/tool_call.py b/examples/tool_call.py
index dc26268..fb1555d 100644
--- a/examples/tool_call.py
+++ b/examples/tool_call.py
@@ -63,9 +63,7 @@ def run(stream: bool = False) -> None:
                     )
                     tool_call["function"]["name"] = chunk.event.delta.function.name
                 if chunk.event.delta.function.arguments:
-                    tool_call["function"][
-                        "arguments"
-                    ] += chunk.event.delta.function.arguments
+                    tool_call["function"]["arguments"] += chunk.event.delta.function.arguments
                     print(chunk.event.delta.function.arguments, end="", flush=True)
 
             if chunk.event.stop_reason is not None:
diff --git a/pyproject.toml b/pyproject.toml
index 936914d..90c0048 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -17,11 +17,10 @@ dependencies = [
   "sniffio",
 ]
 
-requires-python = ">= 3.9"
+requires-python = ">= 3.10"
 classifiers = [
   "Typing :: Typed",
   "Intended Audience :: Developers",
-  "Programming Language :: Python :: 3.9",
   "Programming Language :: Python :: 3.10",
   "Programming Language :: Python :: 3.11",
   "Programming Language :: Python :: 3.12",
@@ -143,7 +142,7 @@ filterwarnings = [
 # there are a couple of flags that are still disabled by
 # default in strict mode as they are experimental and niche.
 typeCheckingMode = "strict"
-pythonVersion = "3.9"
+pythonVersion = "3.10"
 
 exclude = [
     "_dev",
@@ -213,7 +212,7 @@ ignore_missing_imports = true
 [tool.ruff]
 line-length = 120
 output-format = "grouped"
-target-version = "py38"
+target-version = "py310"
 
 [tool.ruff.format]
 docstring-code-format = true