diff --git a/Cargo.lock b/Cargo.lock
index ef69edf6..d0f68252 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2363,7 +2363,7 @@ dependencies = [
  "serde_json",
  "tempfile",
  "test-common",
- "thiserror 2.0.7",
+ "thiserror 2.0.9",
  "tokio",
  "toml",
  "toml_edit",
@@ -2720,7 +2720,7 @@ dependencies = [
  "serde",
  "serde_json",
  "syn",
- "thiserror 2.0.7",
+ "thiserror 2.0.9",
  "typify",
  "unicode-ident",
 ]
@@ -3686,11 +3686,11 @@ dependencies = [
 
 [[package]]
 name = "thiserror"
-version = "2.0.7"
+version = "2.0.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "93605438cbd668185516ab499d589afb7ee1859ea3d5fc8f6b0755e1c7443767"
+checksum = "f072643fd0190df67a8bab670c20ef5d8737177d6ac6b2e9a236cb096206b2cc"
 dependencies = [
- "thiserror-impl 2.0.7",
+ "thiserror-impl 2.0.9",
 ]
 
 [[package]]
@@ -3706,9 +3706,9 @@ dependencies = [
 
 [[package]]
 name = "thiserror-impl"
-version = "2.0.7"
+version = "2.0.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e1d8749b4531af2117677a5fcd12b1348a3fe2b81e36e61ffeac5c4aa3273e36"
+checksum = "7b50fa271071aae2e6ee85f842e2e28ba8cd2c5fb67f11fcb1fd70b276f9e7d4"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -4044,7 +4044,7 @@ dependencies = [
  "serde",
  "serde_json",
  "syn",
- "thiserror 2.0.7",
+ "thiserror 2.0.9",
  "unicode-ident",
 ]
 
diff --git a/Cargo.toml b/Cargo.toml
index 16e31239..4abeaab5 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -54,7 +54,7 @@ serde = { version = "1.0.216", features = ["derive"] }
 serde_json = "1.0.133"
 similar = "2.6.0"
 tabwriter = "1.4.0"
-thiserror = "2.0.7"
+thiserror = "2.0.9"
 tempfile = "3.14.0"
 test-common = { path = "test-common" }
 thouart = { git = "https://github.com/oxidecomputer/thouart" }