diff --git a/Cargo.lock b/Cargo.lock
index 7a14c51..e0d328c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -988,9 +988,9 @@ dependencies = [
 
 [[package]]
 name = "once_cell"
-version = "1.19.0"
+version = "1.20.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3fdb12b2476b595f9358c5161aa467c2438859caa136dec86c26fdd2efe17b92"
+checksum = "33ea5043e58958ee56f3e15a90aee535795cd7dfd319846288d93c5b57d85cbe"
 
 [[package]]
 name = "opaque-debug"
diff --git a/Cargo.toml b/Cargo.toml
index 1be0280..abe1325 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -22,4 +22,4 @@ tracing = "0.1"
 
 [dev-dependencies]
 abscissa_core = { version = "0.7.0", features = ["testing"] }
-once_cell = "1.19"
+once_cell = "1.20"