diff --git a/Cargo.lock b/Cargo.lock
index f9245c5..5644473 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -146,9 +146,9 @@ checksum = "3ee2393c4a91429dffb4bedf19f4d6abf27d8a732c8ce4980305d782e5426d57"
 
 [[package]]
 name = "der"
-version = "0.4.4"
+version = "0.4.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "28e98c534e9c8a0483aa01d6f6913bc063de254311bd267c9cf535e9b70e15b2"
+checksum = "79b71cca7d95d7681a4b3b9cdf63c8dbc3730d0584c2c74e31416d64a90493f4"
 dependencies = [
  "const-oid",
  "crypto-bigint",
@@ -251,9 +251,9 @@ dependencies = [
 
 [[package]]
 name = "generic-array"
-version = "0.14.4"
+version = "0.14.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "501466ecc8a30d1d3b7fc9229b122b2ce8ed6e9d9223f1138d4babb253e51817"
+checksum = "fd48d33ec7f05fbfa152300fdad764757cbded343c1aa1cff2fbaf4134851803"
 dependencies = [
  "typenum",
  "version_check",
@@ -337,9 +337,9 @@ dependencies = [
 
 [[package]]
 name = "libc"
-version = "0.2.108"
+version = "0.2.112"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8521a1b57e76b1ec69af7599e75e38e7b7fad6610f037db8c79b127201b5d119"
+checksum = "1b03d17f364a3a042d5e5d46b053bbbf82c92c9430c592dd4c064dc6ee997125"
 
 [[package]]
 name = "libm"
@@ -538,30 +538,30 @@ dependencies = [
 
 [[package]]
 name = "pkg-config"
-version = "0.3.22"
+version = "0.3.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "12295df4f294471248581bc09bef3c38a5e46f1e36d6a37353621a0c6c357e1f"
+checksum = "58893f751c9b0412871a09abd62ecd2a00298c6c83befa223ef98c52aef40cbe"
 
 [[package]]
 name = "ppv-lite86"
-version = "0.2.15"
+version = "0.2.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ed0cfbc8191465bed66e1718596ee0b0b35d5ee1f41c5df2189d0fe8bde535ba"
+checksum = "eb9f9e6e233e5c4a35559a617bf40a4ec447db2e84c20b55a6f83167b7e57872"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.32"
+version = "1.0.36"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ba508cc11742c0dc5c1659771673afbab7a0efab23aa17e854cbab0837ed0b43"
+checksum = "c7342d5883fbccae1cc37a2353b09c87c9b0f3afd73f5fb9bba687a1f733b029"
 dependencies = [
  "unicode-xid",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.10"
+version = "1.0.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "38bc8cc6a5f2e3655e0899c1b848643b2562f853f114bfec7be120678e3ace05"
+checksum = "47aa80447ce4daf1717500037052af176af5d38cc3e571d9ec1c7353fc10c87d"
 dependencies = [
  "proc-macro2",
 ]
@@ -663,9 +663,9 @@ dependencies = [
 
 [[package]]
 name = "serde"
-version = "1.0.130"
+version = "1.0.133"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f12d06de37cf59146fbdecab66aa99f9fe4f78722e3607577a5375d66bd0c913"
+checksum = "97565067517b60e2d1ea8b268e59ce036de907ac523ad83a0475da04e818989a"
 
 [[package]]
 name = "sha-1"
@@ -682,9 +682,9 @@ dependencies = [
 
 [[package]]
 name = "sha2"
-version = "0.9.8"
+version = "0.9.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b69f9a4c9740d74c5baa3fd2e547f9525fa8088a8a958e0ca2409a514e33f5fa"
+checksum = "4d58a1e1bf39749807d89cf2d98ac2dfa0ff1cb3faa38fbb64dd88ac8013d800"
 dependencies = [
  "block-buffer",
  "cfg-if",
@@ -741,9 +741,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "1.0.81"
+version = "1.0.85"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2afee18b8beb5a596ecb4a2dce128c719b4ba399d34126b9e4396e3f9860966"
+checksum = "a684ac3dcd8913827e18cd09a68384ee66c1de24157e3c556c9ab16d85695fb7"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -803,9 +803,9 @@ dependencies = [
 
 [[package]]
 name = "typenum"
-version = "1.14.0"
+version = "1.15.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b63708a265f51345575b27fe43f9500ad611579e764c79edbc2037b1121959ec"
+checksum = "dcf81ac59edc17cc8697ff311e8f5ef2d99fcbd9817b34cec66f90b6c3dfd987"
 
 [[package]]
 name = "unicode-xid"
@@ -824,9 +824,9 @@ dependencies = [
 
 [[package]]
 name = "version_check"
-version = "0.9.3"
+version = "0.9.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5fecdca9a5291cc2b8dcf7dc02453fee791a280f3743cb0905f8822ae463b3fe"
+checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
 
 [[package]]
 name = "wasi"
diff --git a/src/certificate.rs b/src/certificate.rs
index a9985bc..78855b9 100644
--- a/src/certificate.rs
+++ b/src/certificate.rs
@@ -320,6 +320,7 @@ impl x509::AlgorithmIdentifier for SignatureId {
 #[derive(Clone, Debug)]
 pub struct Certificate {
     serial: Serial,
+    #[allow(dead_code)]
     issuer: String,
     subject: String,
     subject_pki: PublicKeyInfo,