diff --git a/Cargo.toml b/Cargo.toml
index 5e0892f..21d2d87 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,7 +14,7 @@ categories = ["mathematics"]
 crate-type = ["cdylib", "rlib"]
 
 [dependencies]
-approx = "0.3.2"
+approx = "0.4.0"
 
 [dev-dependencies]
 proptest = { version = "0.10.1", default-features = false, features = ["std"] }