diff --git a/Cargo.toml b/Cargo.toml
index e353dcf..1e1b1f7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -17,7 +17,7 @@ Automated tests of FFI bindings.
 [dependencies]
 syntex_syntax2 = "0.0.2"
 cc = "1.0.1"
-rustc_version = "0.2"
+rustc_version = "0.4"
 
 [workspace]
 members = ["testcrate"]