diff --git a/postgres-derive-test/src/lib.rs b/postgres-derive-test/src/lib.rs
index 8bfd147f..d1478ac4 100644
--- a/postgres-derive-test/src/lib.rs
+++ b/postgres-derive-test/src/lib.rs
@@ -16,12 +16,12 @@ where
 {
     for &(ref val, ref repr) in checks.iter() {
         let stmt = conn
-            .prepare(&*format!("SELECT {}::{}", *repr, sql_type))
+            .prepare(&format!("SELECT {}::{}", *repr, sql_type))
             .unwrap();
         let result = conn.query_one(&stmt, &[]).unwrap().get(0);
         assert_eq!(val, &result);
 
-        let stmt = conn.prepare(&*format!("SELECT $1::{}", sql_type)).unwrap();
+        let stmt = conn.prepare(&format!("SELECT $1::{}", sql_type)).unwrap();
         let result = conn.query_one(&stmt, &[val]).unwrap().get(0);
         assert_eq!(val, &result);
     }
@@ -40,12 +40,12 @@ pub fn test_type_asymmetric<T, F, S, C>(
 {
     for &(ref val, ref repr) in checks.iter() {
         let stmt = conn
-            .prepare(&*format!("SELECT {}::{}", *repr, sql_type))
+            .prepare(&format!("SELECT {}::{}", *repr, sql_type))
             .unwrap();
         let result: F = conn.query_one(&stmt, &[]).unwrap().get(0);
         assert!(cmp(val, &result));
 
-        let stmt = conn.prepare(&*format!("SELECT $1::{}", sql_type)).unwrap();
+        let stmt = conn.prepare(&format!("SELECT $1::{}", sql_type)).unwrap();
         let result: F = conn.query_one(&stmt, &[val]).unwrap().get(0);
         assert!(cmp(val, &result));
     }