diff --git a/Cargo.lock b/Cargo.lock
index a3d81a998..3bc9c5fee 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2761,9 +2761,9 @@ dependencies = [
 
 [[package]]
 name = "once_cell"
-version = "1.17.2"
+version = "1.18.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9670a07f94779e00908f3e686eab508878ebb390ba6e604d3a284c00e8d0487b"
+checksum = "dd8b5dd2ae5ed71462c540258bedcb51965123ad7e7ccf4b9a8cafaa4a63576d"
 
 [[package]]
 name = "oorandom"
diff --git a/zebra-consensus/Cargo.toml b/zebra-consensus/Cargo.toml
index deab9ce8b..084cb357f 100644
--- a/zebra-consensus/Cargo.toml
+++ b/zebra-consensus/Cargo.toml
@@ -37,7 +37,7 @@ rayon = "1.7.0"
 chrono = { version = "0.4.26", default-features = false, features = ["clock", "std"] }
 displaydoc = "0.2.4"
 lazy_static = "1.4.0"
-once_cell = "1.17.2"
+once_cell = "1.18.0"
 serde = { version = "1.0.163", features = ["serde_derive"] }
 
 futures = "0.3.28"
diff --git a/zebra-state/Cargo.toml b/zebra-state/Cargo.toml
index 8e2100d83..fe4e18add 100644
--- a/zebra-state/Cargo.toml
+++ b/zebra-state/Cargo.toml
@@ -75,7 +75,7 @@ color-eyre = "0.6.2"
 # Enable a feature that makes tinyvec compile much faster.
 tinyvec = { version = "1.6.0", features = ["rustc_1_55"] }
 
-once_cell = "1.17.2"
+once_cell = "1.18.0"
 spandoc = "0.2.2"
 
 hex = { version = "0.4.3", features = ["serde"] }
diff --git a/zebra-test/Cargo.toml b/zebra-test/Cargo.toml
index fd034a74e..695e9b484 100644
--- a/zebra-test/Cargo.toml
+++ b/zebra-test/Cargo.toml
@@ -13,7 +13,7 @@ indexmap = "1.9.3"
 lazy_static = "1.4.0"
 insta = "1.29.0"
 proptest = "1.2.0"
-once_cell = "1.17.2"
+once_cell = "1.18.0"
 rand = { version = "0.8.5", package = "rand" }
 regex = "1.8.4"
 
diff --git a/zebrad/Cargo.toml b/zebrad/Cargo.toml
index b69396dbc..12a9bcc83 100644
--- a/zebrad/Cargo.toml
+++ b/zebrad/Cargo.toml
@@ -194,7 +194,7 @@ tonic-build = { version = "0.9.2", optional = true }
 abscissa_core = { version = "0.5", features = ["testing"] }
 hex = "0.4.3"
 jsonrpc-core = "18.0.0"
-once_cell = "1.17.2"
+once_cell = "1.18.0"
 regex = "1.8.4"
 semver = "1.0.17"