diff --git a/crates/agent/src/tools/now_tool.rs b/crates/agent/src/tools/now_tool.rs
index 04aba44ff3a1f4..9721c923b6e8d2 100644
--- a/crates/agent/src/tools/now_tool.rs
+++ b/crates/agent/src/tools/now_tool.rs
@@ -13,8 +13,10 @@ use crate::{AgentTool, ToolCallEventStream, ToolInput};
 #[schemars(inline)]
 pub enum Timezone {
     /// Use UTC for the datetime.
+    #[serde(alias = "UTC", alias = "Utc")]
     Utc,
     /// Use local time for the datetime.
+    #[serde(alias = "LOCAL", alias = "Local")]
     Local,
 }