diff --git a/Cargo.lock b/Cargo.lock
index 177d52f9..74b908dc 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1332,9 +1332,9 @@ checksum = "7f24254aa9a54b5c858eaee2f5bccdb46aaf0e486a595ed5fd8f86ba55232a70"
 
 [[package]]
 name = "highs-sys"
-version = "1.11.0"
+version = "1.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "908a51a57402b0616cf0026c0e7bf908cbee7bac13bd45778ba4f2e2ac6bb6db"
+checksum = "9c51d1e4e682c01dd882d2d0cd89b6725cd5805dd307d290aac0a37be6fe0c58"
 dependencies = [
  "bindgen",
  "cmake",
diff --git a/pywr-core/Cargo.toml b/pywr-core/Cargo.toml
index 2df6160e..b2e1daa8 100644
--- a/pywr-core/Cargo.toml
+++ b/pywr-core/Cargo.toml
@@ -33,7 +33,7 @@ coin-or-sys = { path = "../coin-or-sys", version = "0.1.0", optional = true }
 csv = { workspace = true }
 float-cmp = { workspace = true }
 hdf5-metno = { workspace = true, optional = true }
-highs-sys = { version = "1.11", optional = true }
+highs-sys = { version = "1.12", optional = true }
 ipm-ocl = { path = "../ipm-ocl", optional = true }
 ipm-simd = { path = "../ipm-simd", optional = true }
 libc = "0.2"