diff --git a/Cargo.lock b/Cargo.lock
index 52b1e19..7412835 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -288,9 +288,9 @@ checksum = "1a55ca5f3b68e41c979bf8c46a6f1da892ca4db8f94023ce0bd32407573b1ac0"
 
 [[package]]
 name = "syn"
-version = "1.0.86"
+version = "1.0.91"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8a65b3f4ffa0092e9887669db0eae07941f023991ab58ea44da8fe8e2d511c6b"
+checksum = "b683b2b825c8eef438b77c36a06dc262294da3d5a5813fac20da149241dcd44d"
 dependencies = [
  "proc-macro2",
  "quote",
diff --git a/Cargo.toml b/Cargo.toml
index b27a3d7..c3c0159 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -13,5 +13,5 @@ crate-type = ["cdylib", "rlib"]
 [dependencies]
 quote = "1.0.10"
 zip = "0.5.13"
-syn = { version = "1.0.86", features = ["full"] }
+syn = { version = "1.0.91", features = ["full"] }
 pyo3 = { version = "0.15.1", features = ["extension-module"] }  # version corresponds to numpy