diff --git a/Cargo.toml b/Cargo.toml
index 67c2d344..611dc7d2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -21,7 +21,7 @@ log = "0.3"
 libc = "0.2"
 spin = "0.4"
 num-traits = "0.1"
-pyo3cls = { path = "pyo3cls" }
+pyo3cls = { path = "pyo3cls", version="0.1.0" }
 # backtrace = "0.3"
 
 [dev-dependencies]