diff --git a/package.json b/package.json
index 32d7d503b..db76f2c95 100644
--- a/package.json
+++ b/package.json
@@ -119,7 +119,7 @@
     "remark-math": "3.0.1",
     "remark-parse": "8.0.3",
     "search-closest": "3.1.0",
-    "smol-toml": "1.8.0",
+    "smol-toml": "1.9.0",
     "strip-ansi": "7.2.0",
     "to-fast-properties": "4.0.0",
     "trim-newlines": "5.0.0",
diff --git a/tests/unit/config-loader.js b/tests/unit/config-loader.js
index 24f859ec4..2995564b4 100644
--- a/tests/unit/config-loader.js
+++ b/tests/unit/config-loader.js
@@ -24,7 +24,14 @@ describe("Support BOM", () => {
       const file = path.join(directory, filename);
       await fs.writeFile(file, `\ufeff${content}`);
       const config = await loadConfig(file);
-      expect(config).toStrictEqual(expected);
+
+      // `smol-toml` uses a `null` prototype object
+      if (filename.endsWith(".toml")) {
+        // eslint-disable-next-line jest/prefer-strict-equal
+        expect(config).toEqual(expected);
+      } else {
+        expect(config).toStrictEqual(expected);
+      }
     });
   }
 });
diff --git a/tests/unit/invalid-config.js b/tests/unit/invalid-config.js
index 11e4253be..1b6b5e352 100644
--- a/tests/unit/invalid-config.js
+++ b/tests/unit/invalid-config.js
@@ -71,7 +71,7 @@ Cause: Expected property name or '}' in JSON at position 1 (line 1 column 2)"
       loadConfigFile({ filename: ".prettierrc.toml", content: "a=\n  b!=" }),
     ).rejects.toThrowErrorMatchingInlineSnapshot(`
 "TOML Error in "<dir>/.prettierrc.toml":
-Invalid TOML document: incomplete declaration: value expected
+Invalid TOML document: invalid value
 
 1:  a=
       ^
diff --git a/yarn.lock b/yarn.lock
index f6f4f7bc8..35d22a35b 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -8360,7 +8360,7 @@ __metadata:
     rollup-plugin-license: "npm:3.7.1"
     search-closest: "npm:3.1.0"
     serialize-javascript: "npm:7.1.1"
-    smol-toml: "npm:1.8.0"
+    smol-toml: "npm:1.9.0"
     strip-ansi: "npm:7.2.0"
     tempy: "npm:3.2.0"
     tinybench: "npm:6.2.0"
@@ -8789,10 +8789,10 @@ __metadata:
   languageName: node
   linkType: hard
 
-"smol-toml@npm:1.8.0, smol-toml@npm:^1.6.1, smol-toml@npm:^1.8.0":
-  version: 1.8.0
-  resolution: "smol-toml@npm:1.8.0"
-  checksum: 10/eb8aeeebd1c3e5de6069922c9a44bb40b9b3c534e685ccd0aa299b4d7307f1ec49471da57812bdbf1d21a0c09f1dd47eb0e814d0d34c892142187ccce2487ea9
+"smol-toml@npm:1.9.0, smol-toml@npm:^1.6.1, smol-toml@npm:^1.8.0":
+  version: 1.9.0
+  resolution: "smol-toml@npm:1.9.0"
+  checksum: 10/b9953e9b6470eed13c368e0e6674b21fd7a3917c1cdb492570d8dfa568b36e9705b5d072a64052e4375895bc6daef4e76528016c9f13045e81c0d3e092d53e3b
   languageName: node
   linkType: hard