diff --git a/src/statement.rs b/src/statement.rs
index e2bee18..053eef9 100644
--- a/src/statement.rs
+++ b/src/statement.rs
@@ -149,17 +149,6 @@ impl Bindable for i64 {
     }
 }
 
-impl Bindable for () {
-    #[inline]
-    fn bind(&self, statement: &mut Statement, i: usize) -> Result<()> {
-        debug_assert!(i > 0, "the indexing starts from 1");
-        unsafe {
-            ok!(statement.raw.1, ffi::sqlite3_bind_null(statement.raw.0, i as c_int));
-        }
-        Ok(())
-    }
-}
-
 impl<'l> Bindable for &'l str {
     #[inline]
     fn bind(&self, statement: &mut Statement, i: usize) -> Result<()> {
@@ -172,6 +161,17 @@ impl<'l> Bindable for &'l str {
     }
 }
 
+impl Bindable for () {
+    #[inline]
+    fn bind(&self, statement: &mut Statement, i: usize) -> Result<()> {
+        debug_assert!(i > 0, "the indexing starts from 1");
+        unsafe {
+            ok!(statement.raw.1, ffi::sqlite3_bind_null(statement.raw.0, i as c_int));
+        }
+        Ok(())
+    }
+}
+
 impl Readable for Value {
     fn read(statement: &Statement, i: usize) -> Result<Self> {
         Ok(match statement.kind(i) {