diff --git a/router/src/lib.rs b/router/src/lib.rs
index f5ddcc56..4f9637d3 100644
--- a/router/src/lib.rs
+++ b/router/src/lib.rs
@@ -1616,4 +1616,36 @@ mod tests {
             r#"{"role":"assistant","tool_calls":[{"id":"0","type":"function","function":{"description":null,"name":"myfn","arguments":{"format":"csv"}}}]}"#
         );
     }
+
+    #[test]
+    fn tool_choice_formats() {
+
+        #[derive(Deserialize)]
+        struct TestRequest {
+            tool_choice: ToolChoice,
+        }
+
+        let none = r#"{"tool_choice":"none"}"#;
+        let de_none: TestRequest = serde_json::from_str(none).unwrap();
+        assert_eq!(de_none.tool_choice, ToolChoice(Some(ToolType::NoTool)));
+
+        let auto = r#"{"tool_choice":"auto"}"#;
+        let de_auto: TestRequest = serde_json::from_str(auto).unwrap();
+        assert_eq!(de_auto.tool_choice, ToolChoice(Some(ToolType::OneOf)));
+
+        let ref_choice = ToolChoice(Some(ToolType::Function(FunctionName { name: "myfn".to_string() })));
+
+        let named = r#"{"tool_choice":"myfn"}"#;
+        let de_named: TestRequest = serde_json::from_str(named).unwrap();
+        assert_eq!(de_named.tool_choice, ref_choice);
+
+        let old_named = r#"{"tool_choice":{"function":{"name":"myfn"}}}"#;
+        let de_old_named: TestRequest = serde_json::from_str(old_named).unwrap();
+        assert_eq!(de_old_named.tool_choice, ref_choice);
+
+        let openai_named = r#"{"tool_choice":{"type":"function","function":{"name":"myfn"}}}"#;
+        let de_openai_named: TestRequest = serde_json::from_str(openai_named).unwrap();
+
+        assert_eq!(de_openai_named.tool_choice, ref_choice);
+    }
 }