diff --git a/source/orm/query/query_compiler.cpp b/source/orm/query/query_compiler.cpp
index 09738e6..6bf74fd 100644
--- a/source/orm/query/query_compiler.cpp
+++ b/source/orm/query/query_compiler.cpp
@@ -440,7 +440,7 @@ std::string query_compiler::build_table_name(const sql::dialect_token token, con
 }
 
 std::string query_compiler::build_add_constraint_string(const table_constraint &c) const {
-  std::string result = dialect_->add_constraint() + " " + build_constraint_name(c) + " ";
+  std::string result = " " + dialect_->add_constraint() + " " + build_constraint_name(c) + " ";
   if (c.is_primary_key_constraint()) {
     result.append(dialect_->primary_key()).append(" (").append(c.column_name()).append(")");
   } else if (c.is_foreign_key_constraint()) {