diff --git a/packages/toolbox-adk/pyproject.toml b/packages/toolbox-adk/pyproject.toml
index 7f724001b..daf8d6adc 100644
--- a/packages/toolbox-adk/pyproject.toml
+++ b/packages/toolbox-adk/pyproject.toml
@@ -35,7 +35,7 @@ Changelog = "https://github.com/googleapis/mcp-toolbox-sdk-python/blob/main/pack
 [project.optional-dependencies]
 test = [
     "black[jupyter]==26.5.1",
-    "isort==8.0.1",
+    "isort==9.0.1",
     "mypy==2.1.0",
     "pytest==9.0.3",
     "pytest-asyncio==1.4.0",
diff --git a/packages/toolbox-core/pyproject.toml b/packages/toolbox-core/pyproject.toml
index 6e44e0a11..e89b060c2 100644
--- a/packages/toolbox-core/pyproject.toml
+++ b/packages/toolbox-core/pyproject.toml
@@ -50,7 +50,7 @@ telemetry = [
 ]
 test = [
     "black[jupyter]==26.5.1",
-    "isort==8.0.1",
+    "isort==9.0.1",
     "mypy==2.1.0",
     "pytest==9.0.3",
     "pytest-aioresponses==0.3.0",
diff --git a/packages/toolbox-langchain/pyproject.toml b/packages/toolbox-langchain/pyproject.toml
index d586b3dcb..889b4f669 100644
--- a/packages/toolbox-langchain/pyproject.toml
+++ b/packages/toolbox-langchain/pyproject.toml
@@ -45,7 +45,7 @@ Changelog = "https://github.com/googleapis/mcp-toolbox-sdk-python/blob/main/pack
 [project.optional-dependencies]
 test = [
     "black[jupyter]==26.5.1",
-    "isort==8.0.1",
+    "isort==9.0.1",
     "mypy==2.1.0",
     "pytest-asyncio==1.4.0",
     "pytest==9.0.3",
diff --git a/packages/toolbox-llamaindex/pyproject.toml b/packages/toolbox-llamaindex/pyproject.toml
index 9061cbadd..4abed1eb4 100644
--- a/packages/toolbox-llamaindex/pyproject.toml
+++ b/packages/toolbox-llamaindex/pyproject.toml
@@ -45,7 +45,7 @@ Changelog = "https://github.com/googleapis/mcp-toolbox-sdk-python/blob/main/pack
 [project.optional-dependencies]
 test = [
     "black[jupyter]==26.5.1",
-    "isort==8.0.1",
+    "isort==9.0.1",
     "mypy==2.1.0",
     "pytest-asyncio==1.4.0",
     "pytest==9.0.3",