diff --git a/lib/blazer/adapters/sql_adapter.rb b/lib/blazer/adapters/sql_adapter.rb
index 8958301e..c31bfbbe 100644
--- a/lib/blazer/adapters/sql_adapter.rb
+++ b/lib/blazer/adapters/sql_adapter.rb
@@ -44,7 +44,7 @@ def run_statement(statement, comment, bind_params = [])
 
           # fix for non-ASCII column names and charts
           if adapter_name == "Trilogy"
-            columns.map! { |k| k.dup.force_encoding(Encoding::UTF_8) }
+            columns = columns.map { |k| k.dup.force_encoding(Encoding::UTF_8) }
           end
         rescue => e
           error = e.message.sub(/.+ERROR: /, "")