diff --git a/pyproject.toml b/pyproject.toml
index 44fdd6c..017388e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -19,7 +19,7 @@ classifiers = [
 ]
 dependencies = [
     "libcst>=1.1",
-    "mcp>=1.2",
+    "mcp>=1.2,<2",
 ]
 
 [project.optional-dependencies]