diff --git a/src/backend/mysql.rs b/src/backend/mysql.rs
index 5b27c69..d8c4461 100644
--- a/src/backend/mysql.rs
+++ b/src/backend/mysql.rs
@@ -73,7 +73,7 @@ impl SqlGenerator for MySql {
                 false => "",
             },
             match (&tt.default).as_ref() {
-                Some(ref m) => format!(" DEFAULT '{}'", m),
+                Some(ref m) => format!(" DEFAULT {}", m),
                 _ => format!(""),
             },
             match tt.nullable {
diff --git a/src/backend/pg.rs b/src/backend/pg.rs
index 1bea666..26f3bba 100644
--- a/src/backend/pg.rs
+++ b/src/backend/pg.rs
@@ -75,7 +75,7 @@ impl SqlGenerator for Pg {
                 false => "",
             },
             match (&tt.default).as_ref() {
-                Some(ref m) => format!(" DEFAULT '{}'", m),
+                Some(ref m) => format!(" DEFAULT {}", m),
                 _ => format!(""),
             },
             match tt.nullable {
diff --git a/src/backend/sqlite3.rs b/src/backend/sqlite3.rs
index 7c0d043..d04a371 100644
--- a/src/backend/sqlite3.rs
+++ b/src/backend/sqlite3.rs
@@ -71,7 +71,7 @@ impl SqlGenerator for Sqlite {
                 false => "",
             },
             match (&tt.default).as_ref() {
-                Some(ref m) => format!(" DEFAULT '{}'", m),
+                Some(ref m) => format!(" DEFAULT {}", m),
                 _ => format!(""),
             },
             match tt.nullable {