diff --git a/build.rs b/build.rs
index c460933..3dadbc5 100644
--- a/build.rs
+++ b/build.rs
@@ -1,6 +1,6 @@
 #[macro_use] extern crate quote;
+#[macro_use] extern crate diesel;
 extern crate diesel_migrations;
-extern crate diesel;
 extern crate walkdir;
 
 use diesel::Connection;
@@ -11,9 +11,10 @@ use std::io::prelude::*;
 use std::path::Path;
 use walkdir::WalkDir;
 
-use std::ffi::CString;
-fn markdown_to_fts(_: &::diesel::sqlite::Context) -> CString {
-    panic!("Should never be called when running migrations on build.db")
+#[allow(dead_code)]
+mod sqlfunc {
+    use diesel::sql_types::Text;
+    sql_function!(fn markdown_to_fts(text: Text) -> Text);
 }
 
 fn main() {
@@ -23,7 +24,7 @@ fn main() {
 
     let _ignore_failure = std::fs::remove_file(db_path);
 
-    let mut connection = SqliteConnection::establish(db_path)
+    let connection = SqliteConnection::establish(db_path)
         .expect(&format!("Error esablishing a database connection to {}", db_path));
 
     // Integer is a dummy placeholder. Compiling fails when passing ().
@@ -31,12 +32,7 @@ fn main() {
         .execute(&connection)
         .expect("Should be able to enable foreign keys");
 
-    connection.create_scalar_function(
-        "markdown_to_fts",
-        1,
-        true,
-        markdown_to_fts,
-    ).unwrap();
+    sqlfunc::markdown_to_fts::register_impl(&connection, |_: String| -> String { unreachable!() }).unwrap();
 
     diesel_migrations::run_pending_migrations(&connection).unwrap();
 
diff --git a/src/db.rs b/src/db.rs
index a1654f3..b8c73e1 100644
--- a/src/db.rs
+++ b/src/db.rs
@@ -9,11 +9,10 @@ embed_migrations!();
 #[derive(Debug)]
 struct SqliteInitializer;
 
-use std::ffi::CString;
-
-fn markdown_to_fts(ctx: &::diesel::sqlite::Context) -> CString {
-    use rendering;
-    CString::new(rendering::render_markdown_for_fts(&ctx.get::<String>(0))).unwrap()
+#[allow(dead_code)]
+mod sqlfunc {
+    use diesel::sql_types::Text;
+    sql_function!(fn markdown_to_fts(text: Text) -> Text);
 }
 
 impl CustomizeConnection<SqliteConnection, r2d2_diesel::Error> for SqliteInitializer {
@@ -22,11 +21,12 @@ impl CustomizeConnection<SqliteConnection, r2d2_diesel::Error> for SqliteInitial
             .execute(conn)
             .map_err(|x| r2d2_diesel::Error::QueryError(x))?;
 
-        conn.create_scalar_function(
-            "markdown_to_fts",
-            1,
-            true,
-            markdown_to_fts,
+        sqlfunc::markdown_to_fts::register_impl(
+            conn,
+            |text: String| {
+                use rendering;
+                rendering::render_markdown_for_fts(&text)
+            }
         ).map_err(|x| r2d2_diesel::Error::QueryError(x))?;
 
         Ok(())