diff --git a/Cargo.lock b/Cargo.lock
index a1c2c820d..48388cc21 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -323,6 +323,7 @@ dependencies = [
  "const-oid",
  "der_derive",
  "flagset",
+ "heapless",
  "hex-literal",
  "pem-rfc7468",
  "proptest",
@@ -409,9 +410,9 @@ checksum = "37909eebbb50d72f9059c3b6d82c0463f2ff062c9e95845c43a6c9c0355411be"
 
 [[package]]
 name = "flagset"
-version = "0.4.6"
+version = "0.4.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b3ea1ec5f8307826a5b71094dd91fc04d4ae75d5709b20ad351c7fb4815c86ec"
+checksum = "b7ac824320a75a52197e8f2d787f6a38b6718bb6897a35142d749af3c0e8f4fe"
 
 [[package]]
 name = "fnv"
@@ -468,12 +469,31 @@ dependencies = [
  "crunchy",
 ]
 
+[[package]]
+name = "hash32"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "47d60b12902ba28e2730cd37e95b8c9223af2808df9e902d4df49588d1470606"
+dependencies = [
+ "byteorder",
+]
+
 [[package]]
 name = "hashbrown"
 version = "0.15.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bf151400ff0baff5465007dd2f3e717f3fe502074ca563069ce3a6629d07b289"
 
+[[package]]
+name = "heapless"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0bfb9eb618601c89945a70e254898da93b13be0388091d42117462b265bb3fad"
+dependencies = [
+ "hash32",
+ "stable_deref_trait",
+]
+
 [[package]]
 name = "hermit-abi"
 version = "0.5.0"
@@ -1024,6 +1044,12 @@ dependencies = [
  "tempfile",
 ]
 
+[[package]]
+name = "stable_deref_trait"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a8f112729512f8e442d81f95a8a7ddf2b7c6b8a1a6f509a95864142b30cab2d3"
+
 [[package]]
 name = "subtle"
 version = "2.6.1"
diff --git a/der/Cargo.toml b/der/Cargo.toml
index 450972297..9d873451b 100644
--- a/der/Cargo.toml
+++ b/der/Cargo.toml
@@ -21,7 +21,7 @@ arbitrary = { version = "1.4", features = ["derive"], optional = true }
 bytes = { version = "1", optional = true, default-features = false }
 const-oid = { version = "0.10", optional = true }
 der_derive = { version = "0.8.0-rc.0", optional = true }
-flagset = { version = "0.4.6", optional = true }
+flagset = { version = "0.4.7", optional = true }
 pem-rfc7468 = { version = "1.0.0-rc.1", optional = true, features = ["alloc"] }
 time = { version = "0.3.4", optional = true, default-features = false }
 zeroize = { version = "1.8", optional = true, default-features = false }