diff --git a/packages/shared/src/schemaJson.test.ts b/packages/shared/src/schemaJson.test.ts
index c808a9b7c51..4a4d16da0b3 100644
--- a/packages/shared/src/schemaJson.test.ts
+++ b/packages/shared/src/schemaJson.test.ts
@@ -57,6 +57,15 @@ Done.`),
     expect(() => decodeLenientJson('{ "enabled": true,, }')).toThrow();
   });
 
+  it("preserves commas before brackets inside string values", () => {
+    // A comma inside a string value that happens to precede `}`/`]` must not
+    // be stripped as if it were a trailing comma.
+    expect(decodeLenientJson('{"note":"a,]"}')).toEqual({ note: "a,]" });
+    expect(decodeLenientJson('{"list":["x,}"]}')).toEqual({ list: ["x,}"] });
+    // Genuine trailing commas are still removed.
+    expect(decodeLenientJson('{"values":[1, 2,],}')).toEqual({ values: [1, 2] });
+  });
+
   it("formats schema failures with paths without exposing invalid values", () => {
     const decodeCredential = decodeJsonResult(Schema.Struct({ token: Schema.Number }));
     const decoded = decodeCredential('{"token":"credential=secret-value"}');
diff --git a/packages/shared/src/schemaJson.ts b/packages/shared/src/schemaJson.ts
index 04d26d9c229..77b1fa5d548 100644
--- a/packages/shared/src/schemaJson.ts
+++ b/packages/shared/src/schemaJson.ts
@@ -190,8 +190,14 @@ const parseLenientJsonGetter = SchemaGetter.onSome((input: string) => {
     (match, stringLiteral: string | undefined) => (stringLiteral ? match : ""),
   );
 
-  // Strip trailing commas before `}` or `]`.
-  stripped = stripped.replace(/,(\s*[}\]])/g, "$1");
+  // Strip trailing commas before `}` or `]`. The alternation preserves quoted
+  // strings so a comma inside a string value (e.g. `{"note":"a,]"}`) is not
+  // mistaken for a trailing comma and removed.
+  stripped = stripped.replace(
+    /("(?:[^"\\]|\\.)*")|,(\s*[}\]])/g,
+    (match, stringLiteral: string | undefined, bracket: string | undefined) =>
+      stringLiteral ? match : (bracket ?? ""),
+  );
 
   return decodeJsonString(stripped).pipe(
     Effect.map(Option.some),