--- a/langkit/templates/project_file.mako	2017-07-11 14:19:12.841221846 +0200
+++ b/langkit/templates/project_file.mako	2017-07-11 14:12:39.104981170 +0200
@@ -111,6 +111,7 @@
                   --  ... and this prevents OOM on other platforms
             end case;
       end case;
+      for Driver ("C") use External ("GCC", "gcc");
    end Compiler;
 
    package Binder is
--- a/langkit/compile_context.py	2018-07-04 19:17:08.329346507 +0200
+++ b/langkit/compile_context.py	2018-07-04 19:17:57.276615724 +0200
@@ -1684,7 +1684,7 @@
             generate_lexer
         ):
             quex_py_file = path.join(os.environ["QUEX_PATH"], "quex-exe.py")
-            subprocess.check_call([sys.executable, quex_py_file, "-i",
+            subprocess.check_call(["quex", "-i",
                                    quex_file,
                                    "-o", "quex_lexer",
                                    "--buffer-element-size", "4",