diff --git a/pyproject.toml b/pyproject.toml
index 8b35d0f..cc54938 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -43,10 +43,10 @@ Security = "https://github.com/SourceShift/InterLock/blob/main/SECURITY.md"
 
 [project.optional-dependencies]
 mcp = ["wrapt>=1.15"]
-langchain = ["langchain-core>=0.3,<0.4"]
+langchain = ["langchain-core>=0.3,<1.8"]
 # ruff is pinned here too: CI pins it (an unpinned linter turns a green repo red
 # on a release schedule), and a contributor should run the same version as CI.
-dev = ["pytest>=7", "langchain-core>=0.3,<0.4", "ruff==0.16.9",
+dev = ["pytest>=7", "langchain-core>=0.3,<1.8", "ruff==0.17.2",
        # scripts/check_site.py reads the Zensical TOML; tomllib is 3.11+
        "tomli>=1.1; python_version < '3.11'"]