diff --git a/pyproject.toml b/pyproject.toml
index acee956e0b..235bbb8185 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -132,7 +132,7 @@ lsp = [
     "sse-starlette>=0.2.2",
     "pyarrow",
     # For lsp
-    "pygls",
+    "pygls>=1.2.0,<2.0.0",
     "lsprotocol",
 ]
 risingwave = ["psycopg2"]