diff --git a/Cargo.toml b/Cargo.toml
index 4f55181..be5ac1e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -22,4 +22,4 @@ path    = "mongoc-sys"
 version = "1.6.3"
 
 [dev-dependencies]
-chrono = "> 0.2.0"
+chrono = "= 0.3.0"