diff --git a/Cargo.toml b/Cargo.toml
index 0773cd3..a632a30 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,7 +12,7 @@ license = "BSD-3-Clause"
 repository = "https://github.com/castelao/GSW-rs"
 keywords = ["oceanography", "seawater"]
 categories = ["science", "no-std"]
-rust-version = "1.59.0"
+rust-version = "1.68.0"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html