diff --git a/.changeset/gentle-tools-nail.md b/.changeset/gentle-tools-nail.md
new file mode 100644
index 00000000000..460db34e43f
--- /dev/null
+++ b/.changeset/gentle-tools-nail.md
@@ -0,0 +1,5 @@
+---
+"@effect/schema": patch
+---
+
+change trimmed json-schema pattern
diff --git a/packages/schema/src/Schema.ts b/packages/schema/src/Schema.ts
index 2df143c957b..c06742f8b6c 100644
--- a/packages/schema/src/Schema.ts
+++ b/packages/schema/src/Schema.ts
@@ -3563,7 +3563,7 @@ export const trimmed =
       filter((a) => a === a.trim(), {
         typeId: TrimmedTypeId,
         description: "a string with no leading or trailing whitespace",
-        jsonSchema: { pattern: "^.*[a-zA-Z0-9]+.*$" },
+        jsonSchema: { pattern: "^\\S.*\\S$|^\\S$|^$" },
         ...annotations
       })
     )