diff --git a/Cargo.toml b/Cargo.toml
index df44e94..da78b18 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -13,14 +13,12 @@ keywords = ["math", "statistics", "histogram", "bioinformatics", "molecular-dyna
 clap = {version="2.32.0", features=['yaml']}
 error-chain = "0.12.0"
 rand = "0.5.5"
-GSL = "1.0.0"
+GSL = "1.1"
 rayon = "1.0.3"
 
 [dev-dependencies]
 assert_approx_eq = "1.1.0"
 
 [profile.release]
-opt-level = 2
+opt-level = 3
 
-[features]
-default = ["GSL/v2"]