diff --git a/pyproject.toml b/pyproject.toml
index 000f298..d77ae51 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -8,7 +8,7 @@ readme = "README.md"
 
 [tool.poetry.dependencies]
 python = "^3.10"
-launchdarkly-server-sdk = ">=9.16.0"
+launchdarkly-server-sdk = ">=9.16.0,<10.0.0"
 halo = ">=0.0.3"