diff --git a/Cargo.lock b/Cargo.lock
index 47f88c7d..825110c1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -274,9 +274,9 @@ dependencies = [
 
 [[package]]
 name = "critical-section"
-version = "1.1.3"
+version = "1.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f64009896348fc5af4222e9cf7d7d82a95a256c634ebcf61c53e4ea461422242"
+checksum = "6548a0ad5d2549e111e1f6a11a6c2e2d00ce6a3dafe22948d67c2b443f775e52"
 
 [[package]]
 name = "crossbeam-channel"
@@ -729,9 +729,9 @@ dependencies = [
 
 [[package]]
 name = "once_cell"
-version = "1.20.0"
+version = "1.19.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "33ea5043e58958ee56f3e15a90aee535795cd7dfd319846288d93c5b57d85cbe"
+checksum = "3fdb12b2476b595f9358c5161aa467c2438859caa136dec86c26fdd2efe17b92"
 dependencies = [
  "critical-section",
  "portable-atomic",
@@ -868,12 +868,9 @@ dependencies = [
 
 [[package]]
 name = "portable-atomic"
-version = "1.7.0"
+version = "1.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "da544ee218f0d287a911e9c99a39a8c9bc8fcad3cb8db5959940044ecfc67265"
-dependencies = [
- "critical-section",
-]
+checksum = "7170ef9988bc169ba16dd36a7fa041e5c4cbeb6a35b76d4c03daded371eae7c0"
 
 [[package]]
 name = "ppv-lite86"
diff --git a/k256/Cargo.toml b/k256/Cargo.toml
index ef44dea0..21da9070 100644
--- a/k256/Cargo.toml
+++ b/k256/Cargo.toml
@@ -23,7 +23,7 @@ cfg-if = "1.0"
 elliptic-curve = { version = "0.14.0-rc.0", default-features = false, features = ["sec1"] }
 
 # optional dependencies
-once_cell = { version = "1.20", optional = true, default-features = false }
+once_cell = { version = "1.19", optional = true, default-features = false }
 ecdsa-core = { version = "=0.17.0-pre.7", package = "ecdsa", optional = true, default-features = false, features = ["der"] }
 hex-literal = { version = "0.4", optional = true }
 serdect = { version = "0.2", optional = true, default-features = false }