diff --git a/pyproject.toml b/pyproject.toml
index 85b069a..ee579c5 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -18,7 +18,7 @@ classifiers = [
 [project.optional-dependencies]
 api = ["fastapi>=0.115", "asyncpg>=0.30", "uvicorn>=0.34", "pydantic>=2.0"]
 vault = ["hvac>=2.0"]
-dev = ["pytest>=8.0", "pytest-asyncio>=0.24", "ruff>=0.8", "mypy>=1.13", "httpx>=0.28"]
+dev = ["pytest>=8.0", "pytest-asyncio>=0.24", "ruff>=0.8", "mypy>=1.13", "httpx>=0.28", "cryptography>=43.0"]
 
 [project.scripts]
 claude-memory-server = "claude_memory.mcp_server:main"